Mars,
their ancients and such are 25mm old school (think Ral Partha). Their Charlie Company Vietnam War figures are IIRC 1/72 scale, however its been literally years since I last saw them in person, so my memory could be faulty here…
Their Baker Company WW2 vehicles and ordinance are indeed 20mm scale, closer to 1/72 scale than 1/76. I have quite a few of their Hotchkiss H38/39s, Renault R35/39s, Panhard P178s, and Lorraine 37SL tracked APCs, plus a couple of the RSO tractors and one each of the AB41 Autoblinda armored cars.
They socket in just perfectly with 1/72 scale plastics, FAA metal figures, and Raventhorpe vehicles, but are a bit on the larger size for SHQ or Britannia figures.
The Lorraine tractor featured on the RAFM online store is in fact one from my collection:
I painted 'er up many years ago and Jack van Schaik Himself photographed the model at a West Coast Origins where I had the model on display.
Hope this helps!
Leland R. Erickson
Metal Express
metal-express.net