Nick, for the off-decade censuses in the US, they are often taken at the state level, so in addition to the country selector, we would need some place to note which state census is involved. [see note below]
The ones I have used most recently are from Iowa -- the collection on Ancestry includes 1856, 1885, 1895, 1905, 1915, and 1925.
These links may be helpful, though their listings are not complete:
http://www.genealogybranches.com/statec ... cords.html
http://www.researchguides.net/census/state.htm
Edited to add: If you have a census household in 1885 and they live in Iowa, it is obviously the 1885 Iowa State Census and not the 1885 Florida State Census. [oops]
Presumably the user could put the 'official' title of the source in notes, choose the style of naming the image as we do now in Gedcom Census, or edit the Source Title in Family Historian as we see fit.
But if we could teach the program when census day was for each state census, that would be awesome. IMHO auto-filling the the microfilm roll numbers or other ID numbers (as you do now for the RG numbers in the UK Censuses) is less critical, though others may disagree...
I leave it to you to find the most elegant programming solution. [wink]
Jan