House numbers weren’t introduced in rural Ireland till well through the 1900s, so it’s going to be tricky locating this pub. I don’t know of a local map that marked where it was but perhaps there might be one. There is a photo of the main street in Shercock on this site:
http://www.myhometown.ie/41/view_of_main_street/110.html
You could try the Breifne Historical Society to see if they can assist:
http://www.breifnehistory.com
Also try Cavan Library in case they have any historical material on Shercock:
http://www.cavanlibrary.ie/Default.aspx?StructureID_str=33
Here’s what looks to be the same family in 1911, with Michael having remarried to Mary O’Reilly:
http://www.census.nationalarchives.ie/pages/1911/Cavan/Shercock/Shercock_Town/336297/
1906 marriage certificate:
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1906/10114/5680487.pdf
In both 1901 & 1911 there was a shop assistant living there. That suggests to me that it was the typical old fashioned Irish pub that combined a bar with a grocers shop. So half of it would be a bar and the other half would sell potatoes and other things you would get in a grocers.
In that 1911 census, there’s another pub on one side and a shop on the other. But there were 5 pubs and a hotel in the town, so sorting one from another may be hard.
The Valuation Revision records in the Valuation Office in Dublin should show who the neighbours were, right up to 1929 (assuming the family still owned it then). You might be able to use that information to narrow the search.
If you don’t get any help from the sites I have suggested. Asking locally might be the answer. Most towns and villages have a local historian etc.