I concur that whatever is required to get your vintage MIL radio going is generally ok. Especially under the chassis. I've had the experience if doing a quantity of '348 receivers, preferring the "other than" J, N, and Q models. I just think the others are a bit easier to mechanically disassemble, where required. This is not to say that the J, N, and Qs aren't good radios, especially the easy to find tubes.