The decision is yours. From your description, these are the open side ACF covered hoppers with the large square loading hatches? The build date of 1949 sounds about right. There is a basic '40 year' rule for rolling stock. It either needs a complete rebuilding(frame) or needs to banned from interchange service(cannot run on another railroad). With this in mind, 1989 is the 'bingo' date when a decision had to be made about the status of the car. In the 80's, one would still see cars still in their original NP or SLSF paint schemes(the SLSF was just merged into the BN). By the 90's, these older cars would start their journey to the scrap yard or be rebuilt if it was worth it. I have not seen any of the ACF cars for some time, and the only examples I have seen 'rebuilt' were some that were converted to to 'ballast' cars with most of the roof opened up and ballast doors replacing the usual discharge gear. The C&NW had some of these - Eastern Car Works makes a model of this car. Here is a link to a photo of the car - note the special ballast doors.
http://www.walthers.com/exec/productinfo/117-2200
Jim Bernier
Modeling BNSF and Milwaukee Road in SW Wisconsin
Well, the decision really lies in your hands. You have to ask yourself if it is worth the hassle of e-baying it, or should you just keep it and let your prototypical standards slack just a bit. I would probably keep it if I didn't have too much invested in it and I didn't have a major problem with putting it on the layout being a bit out of era. Heck, as far as CSX goes, they probably are still running hoppers from 1949! Good luck.
-beegle55
TONY
"If we never take the time, how can we ever have the time." - Merovingian (Matrix Reloaded)