I am just about finished with my latest army train flatcar. I did the gunjeep last year and have been working on the gun truck Snoopy II this year. It is from a Revell re-issue of an old Renwal 5 ton wrecker kit. It is in 1/32nd scale, which looks better with our trains. Usual military scale is 1/35.
Here are some closeups of the gun truck. Both vehicles were in my company, the 444 Trans near Qui Nhon, Vietnam.
The lettering is printed on Paplio ink jet vinyl from files I made on my computer.