Do some research on the Web under rail buses and gas electric cars. You never know what will jump out at you. Also check for Railroad Cyclopedias as there were at least two editions that had those. Hard to find in print now and may have to search the web.
You will have to do that. You might have to lower the cab end, as well. If you plan to leave it where it is, you will have to put a steam locomotive driver pair under it. One more thing to do is to cut a passenger door into the side and add some steps. NYNH&H had some rail busses that looked like late 1940s-early 1950s Greyhound busses on rails. I do not know how long they lasted. Marklin or Fleischmann, I forget which, sold a trio of Austrian rail busses. There was one powered unit and two dummies. They were four axles. They came with Rapido couplers. The bus bodies look very European. I actually have the trio, but it has been a while since I have looked at them, never mind run them; hence my not even remembering which German firm manufactured them.
Well, saw a pic somewhere where one of the Bachmann PCC shells were put on a chassis similar to the Tomytec one. Having one of the PCCs from the 80s in the cockroach mode, I pulled the body off it and it fits the Tomytec chassis! Looks pretty good too. Tried to take the lettering off the sides, bu it ignored Microsol and Oops, so it will have to just be painted over [or else the Chicago Transit Authority is missing one of it's streetcars. [My guys have a penchant for "Midnight requisitioning"].
Well back at it again and making headway. Using John Moore's suggestion I am using a Kato 106 chassis and some 3D prints. Stretched the body length on the Hoosac caboose so it will fit the chassis right and found another railbus to supply the front half. https://www.thingiverse.com/thing:5890490 https://www.thingiverse.com/thing:5139239 Will post pics later.
Okay, here is a quick pic of what is going on. The railbus with the compartment on one end is fitted to the Kato 105 chassis and works well, however, it is not quite what I wanted. The other drover caboose body fits on the same chassis and would have the bus cut in half, which would then get a 4 wheel truck with coupler installed underneath it. The idea being that will allow the Goose to follow any curves. And yes, both bits will get weighted.
