Their firearms seem to have been overshadowed by Winchester. I have 5 books dedicated to Winchester and only one to Remington.
Rabbit, it should not be difficult to add intro grade Model 31 to your collection. Remi made 189,243 guns which includes 117,739 12ga, 40,312 16ga, and 31,192 20ga. Within last 3 months I have seen two 20s, but each with crack(s) in forend wood-breech end which is something to examine for. Honestly I have rarely looked in used rack of "trombones", so I am not sure how prevalent they really are. I picked up sub 6lb 12ga in very good shape, because something so smooth, graceful, ugly and CHEAP just had to be rescued!
With some 35 variants there are bound to be some rare birds out there, and much to hold ones interest.