Thanks for posting, and good sleuth work so far.
The R stands for Rectifier and like the Distiller # was an identifier. You will find a discussion of the term here:
http://www.filsonhistorical.org/archive/newsv6n3distilling.html
That logo could be tough... Usually it involves brute force digging through eBay looking for bottle matches and hoping to find a labeled example.
Good luck, do report back anything you find.