Walthers/Train Miniature Boxcars without frames

[gna]

I bought some old Train Miniatures/Walthers Boxcars, and some bare bodies were thrown in:

   

   

They look to be Double Sheath Wood cars. Would a fishbelly frame be correct for these cars? I tried an Accurail frame in one of the bodies. It was long, but I think I could shorten it a bit. I could also try a Tichy frame. Also, were brake wheels really that big?

Gary