I am planning a small-scale diorama depicting a scene at a WW2 military vehicle show, with a commercial truck offloading a military vehicle, ready to join the other exhibits at the event.
My question relates to the load carrying capacity of a three-axle lorry (with twin wheels on the rear two axles). The lorry in question is a Mercedes-Benz Eurocab (fixed body), which I intend to convert into a 'beavertail' low-loader. I need to work out what such a lorry would be able to carry, as this will determine the type of WW2 vehicle to be added. Any suggestions welcome.

Thanks.

You can probably find that information from the DOT of the country this military vehicle show will be in.
For example: USA
https://ops.fhwa.dot.gov/Freight/sw/index.htm