Hi, Ric
The Intermountain F series shells were originally designed to fit the Stewart/Bowser/Kato drive chassis.
Bowser used to sell the chassis only, with or without sound, but I don't see any presently listed on their site but some shops or internet sources may have them. Sometimes you can find a better deal on a Stewart/Bowser F series with a shell.
For example:
https://tinyurl.com/yd6tvmth
Other manufacturers' chassis would fit with a little carving and a method to retain the shell on the chassis as Broadway, Athearn Genesis or Proto (Walthers) use different methods of retaining the shell to the chassis.
There has been some discussion previously:
http://cs.trains.com/mrr/f/88/t/252326.aspx
Good Luck, Ed
Can anyone tell me if there is a chassis that will accept an Intermountain F-7 shell, besides an Intermountain chassis? Any help is much appreciated.
RicZ