The Jeepster is kind of an unknown animal to us, but I will share what is only an opinion.
The 2WD trucks, 4WD trucks, Sedan Deliveries and Station Wagons shared pretty much a common frame that could handle up 5200 pounds GVW, with cutouts for PTO shafts, carrier bearings and all sort of miscellaneous auxiliary equipment.
On the other hand, the Jeepster was a lightweight runabout.
I suspect that the frames are going to be different.
A question - do you have frame problems with your Jeepster?