Hello Luke.
I've found your tree on Ancestry.com, and will leave a message on your "uncle" Thomas Grogan's page. I don't think that's him with his mother in the 1861 England Census, and I'll explain that in my "comment" on his profile page.
However, I've had no luck at all finding the Grogan family in Moyleen in the 1856 plot maps of Griffiths Valuations. You can email me if you'd like, and I can explain more. Basically, the valuations were done between 1847 thru 1864. I did find the Quinn and Fahey families living in Moyleen, with a family name of Mannion living between the two. I think that in 1856, Mr. Mannion lived there, but might have sold property to the Grogans after Michael got back from the Civil War in 1865. It's even possible that Mannion was a man that one of the Grogan daughters married, to keep the land in the family... don't know, but you MIGHT be able to find a land purchase in that area, if the National Archives has that information.
These 3 families, Quinn, Mannion and Fahey all lived along the road heading to Dublin, just outside of Loughrea. I used the information that your Aunt wrote about (a LOVELY story, by the way!) and went to "google.maps" and searched the road east of Loughrea until I saw Moyleen. Then I went to Griffith's Valuation maps and found it, as it was plotted back in 1856 era.
Here is the link for all the residents of Moyleen in the Valuation: http://www.askaboutireland.ie/griffith-valuation/index.xml?action=doNameSearch&PlaceID=550337&county=Galway&barony=Loughrea&parish=Loughrea&townland=Moyleen>
If this link doesn't work, please let me know and I will try another way. You will see there are 13 listed names for living in Moyleen, and Grogan isn't one of them. Now, find Laurence Fahey's name in the list, then look to the right on his line, under the column titled "Map Views", and click the larger of the 2 "search" icons. A map will appear in a new window. The first thing you need to do is find the "left to right" scroll bar located in the upper right corner. Drag that bar a little to the left so it shows 1/2 of the new maps, and 1/2 of the old "redish" colored map. (I mean they literally overlap each other and are opague). Basically, you want to see the roads/towns as they are called today, as well as, the old style plot map. Next, in the upper left corner of the screen, click the "+" sign and zoom in about 4 clicks... by this time you should see "Moyleen" taking up your full screen. Now, drag the "left to right" scroll bar (located in the upper right corner) all the way to the right, and you will only see the old version of the map. This process allows you to locate your town easier using modern maps, then allows you to see the old version plot maps crystal clear, and easy to read.
So, once you've done all the above, you will notice plots 8, (the Quinn family), 9 (the Mannion family) and 10a (the Fahey family). Notice that at plot #9, there is a very sharp bend in the road.... I think that's "Grogan's bend" that Mr. Fahey spoke about to your Aunt. However, plot #9 is very large, and Mr. Fahey said it was a small piece of land... again, a lot has changed since 1856, and there's no way to determine if another family purchased some of the Grogan land and/or if Mr Mannion was indeed an in-law and kept some of the land for his own kids, and/or Mannion sold some of it prior to Michael purchasing it... Lord knows what!
I did find that Mr. John Quinn and the Fahey family was living in Moyleen in the 1901 census, and then the Fahey family was still there in the 1911 census. So, the man your Aunt spoke to back in 1974 was probably talking about his grandfather Thomas Fahey, the head of the house in 1901 and 1911.
What I'd like to know more about is the Tithe Applotment you've got for your gr gr gr grandfather Patrick Grogan in 1827... that shows Moyleen, and I'd be very interested in seeing that original record! I really think that particular item will pin down and clarify just where the family lived.
To sum up, unless the Mannions were related, I can't find the Grogan's living in that area of Moyleen in 1856. I can, however, find them in the Loughrea area, but a little farther east and south, located in Carrowroe, in the parish of Kilcooly. (zoom out of the map a couple of clicks until you see "Kilmeen" directly south of Moyleen, and then you will see "Kilcooly" directly east of that.) So, there were Grogans in the area, and there were other Grogans in Galway county, a total of 17 families, some w/in a 25 mile radius of Loughrea.
I also looked on www.findagrave.com, and went to the Garrybreeda Cemetery (link: http://www.findagrave.com/cgi-bin/fg.cgi?page=cr&GSmcid=47395800&CRid=2368601&pt=Garrybreeda%20Cemetery& ) as well as, the Carmelite Abbey Cemetery (link: http://www.findagrave.com/cgi-bin/fg.cgi?page=cr&GSmcid=47395800&CRid=2335906&pt=Carmelite%20Abbey%20Cemetery& ), and didn't find any Grogan names listed. That doesn't surprise me because those very old stones have faded to the point of "can't read it at all". And Garrybreeda isn't fully documeted and I haven't found a place that has the old internment register yet.
If you need help with any of the above, please feel free to email me at MNAJPA@aol.com, and I will see if I can't do anything else, or give you other ideas to check.
One thing I didn't mention is that I have access to the films of the old Catholic Church records of Loughrea, and some other towns in the Clonfert Diocese. In researching my own family from Loughrea, I've ordered the micro films so many times it's now on permanent loan to a local LDS church, and it's litterally a mile from my house. It would be a few weeks before I could get down there, though, as my daughter is getting married next week and I'm buried in "wedding stuff". Doing this kind of research, like what I've done for the Grogans, is easy to do from my home and I don't mind at all. I can also explain how you can acess these same micro films yourself, using the library at an LDS Church near you. The rates are very low ($7 US dollars) for a 6 week loan, and their hours for accessing the films are flexable. Films usually arrive (in the US) within 2 weeks.
Another thing I kept thinking about was that if you hunt down Patrick's other children, that didn't go to Australia, you might find more about Patrick. Maybe one of the other daughter's married and stayed in the Loughrea area... but it will be hard to find if they got married prior to 1864, when Catholic's were "allowed" to register with the civil authorities. But the old church records will still be there!
Thank you! I truly loved reading your Aunt's story... she wrote wonderfully!
Mary Van Dyke