Museums probably not.... *LINK*

I find that MOST museums are not in anykind of financial or orginizational shape to acuire and then dispaly most things that they get.
I know of to many people, who have donated a box of photos, paperwork, or old memorbilia only to find little or no record of it at that location just a few years later.
First off, to the collector, they need to get a coherent plan for their collection BEFORE they die. To many collections are "highly valuable" and "one of a kind" items, for the mere reason that they are owned by the collector. "Nobody else has this photo" - when you can find three of them on Ebay every day of the week. So try and get some kind of list of the items that you are wanting to preserve with a museum, and get peers, relatives, local historians to weigh in on how "rare" the stuff is anyhow.
Once you get a list of items that are deemed hostorically relevant, try to get some kind of geographical signifigance to those items, CRRM and CSRRM are only a letter apart, but the Colorado Railroad Museum and the California State Railroad Museum have a very different clientel (other than us foamers). To many collectors think that THEIR legacy is so important as the collector that the collection should not be "broken up". On the contrary, to the researcher, there is nothing more frustrating than to set in the "Pennsilvania RR museum" looking for photos of trolleys in Pittsburg, only to have to search through fifteen boxes of San fransico Worlds Fair trolley photos. Send the stuff "home" if possible - yes that means splitting the collection where applicable.
As mentioned aboave, once you have found a applicable "home" for geographically or otherwise sorted items from your collection, find a museum that A) answers the phone, hase a staff archivist (if not they are probably to small of an organisation for really historical documents, C) has a procedure for installing your items in to their collection and a sytem for finding and displaying them later.
This last one is the real point, if your "one of a kind" photo of the D&RG #1 engine MOUNTAINEER will be filled by a college kid, in a file cabinet on the second floor, and future researchers will have no way of accessing the photo, then what good did it do anyone?
As for me, I like to think that capitalism is the cure for most ill's and that rarity is rewarded with $$$$$. If your 1962 D&RG timetable from Salida Colorado does not sell for two dollars, even if you include thirteen other ones, then maybe the only people and orginzations on the planet that care, already have a copy!
As stated below, put it up for auction, and let the good times roll, there are several reputable "RR memorobilia" auction houses out there and if your really do have "the chair that Otto Mears set in" then the museums need to belly up to the bar and buy it. For although there are stories (as recently spoofed ???? or not ??? on this board about the insane Doctor RR man who burns his collection rather than passing it on, 99.9% of the RR collectors that I have met have voiced a true love for preserving what they collect, and I can tell you from personal experience that most museums are a blithering disfunctional cash strapped orginsations that once in a blue moon find a way to display or other wise show their collections to the public, while most of the time your precious piece of memorbilia is left up to the whims of an archivist, board, or "director" who play with your stuff and hope that the janitors don't take it out.
Below is a link to what I think is a class act company.
Rodger Polley