Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!
Unfortunately they are not the same as the older J-trucks. They can be made to fit but the radiator support has to be moved. The M725 is the same radiator as the more common M715, but even then finding a new one will be next to impossible. Post up that you are looking for one in the wanted parts section on the www.m715zone.com and I'm sure somebody will have a decent take-out one. Or you can search there as there are several "replacement" radiator that people have been able to make work.Probably any old Jeep "J series" truck. J10 up to J30.