HJ,
The service manual available from the Prevost Car web site will get you all the chassis information, but you still need to know the specific coach because in the vintages you consider you could have a solid axle or IFS and that affects turning radius. The age of the coach can affect axle weight ratings. Some converters use standard fuel others get the optional long range. Just be aware as you look at coaches you need to know serial numbers to learn some information, or at the very least how the converter specced out the shell.
Other information beyond the chassis is strictly converter information and you have to go to them for things like holding tank capacities.
Don’t suffer paralysis by analysis. You will drive yourself nuts. All share the Prevost chassis, and all converters made a great product.
Jeff and Lindsay
91 Marathon XL