mine is the later version with stamped steel frame and uses the Lionel #8 body. Probably the 1928 version.
Unfortunately that is going to be a harder motor to find at a reasonable price. Those are such good motors that people don’t part with them often.
A serviced one with new wheels (usually required) tends to be valued around $200 or more.
MTH did make that locomotive, but I’m not sure how the mounting holes would line up with the frame. Their motors are also around $200 if they have one to sell.
Personally I believe your best option would be to monitor online auctions and wait for a junker loco/set and try to get it reasonable. Steal the motor and sell off the remaining stuff.