One of my M-truck friends asked me where the firewall insulator pad was
listed in the parts catalog, so that we could check part numbers, mounting
hardware, etc.  I couldn't find it in the parts book, not listed, no
drawing.  This is a heavy cardboard pad that goes inside the cab against the
firewall.  I also checked the chassis parts and body parts catalogs for the
'36-'46 cars, but no firewall liners are shown.  Then I noticed that the
seats are not listed in the M truck book, and only front seats show up in
the car book.  Stude International and other vendors list the parts in their
catalogs or web sites, but with non-Stude part numbers.  Was there a
separate set of parts catalogs for upholstery items like firewall insulator
pads and seats?  If so, where do you get those?  Minor mystery, but
fascinating.