I found a old bachmann Burlington 40ft gondola, and weathered it. But my question is that since Burlington Northern in 1970 (or something like that), and I was wondering if i could put a patch on it and it would prototypical?
I’m sure you could put a patch on it and make it at least plausible if not prototypical. I, myself, haven’t seen a BN 40’ gon but that’s not to say they are not out there. I have seen NP chip cars patched for BN a couple of years ago. Once in a while I see a short (looks shorter than 40’) gon in the local Youpee yard. It may be in MOW service. What kind of patch were you thinking of? You might try this link for pictures http://www.railcarphotos.com/Search.php?SearchType=Gondola&Search=Search&PageNumber=1 They have over 2700 photos of gondolas.
41-6 6 554500-554648 this series and all the above have inside height approx 4-7
40-6 1 569820-569846 inside height 5-4
41-6 1 571500-571695 inside height 4-5
40 1 572017 inside height 5-1
41-6 1 572250 inside height 4-5
There are two series that have much more capacity than the quantity would imply. I think these are probably number series set up by BN to receive re-numberings from predecessor roads.