Hi - came across this if anyone wants to add some texture or a realistic cinder block look (or a different look) to the walls of the building of this excellent mod.
I figure HO scale would work, although I think it might be a bit on the large size (but I think N scale would be far too small).
Scroll down for other patterns.
http://www.micromark.com/Cinder-Block-Paper-4-Sheets-HO-Scale,8337.html
edit: also have plastic sheets of various patterns:
http://www.micromark.com/jtt-plastic-pattern-sheets-ho-scale-dressed-stone-75-x12-sheets-2-sheets-per-pkg,10414.html