Good Day, Andrew.
I assume these are actual SCR-274N Army sets
and not AN/ARC-5 or ARA (three different models, all usually
and incorrectly lumped together as "ARC-5").
Unless these are uncommon sets- which would be black wrinkle
and have a tag marked both "SIGNAL CORPS US ARMY" and
"AIRCRAFT RADIO CORP," and have a contract of 1470-NY-41,
then they sound too far gone
for reasonable restoration efforts. Later version
SCR-274N receivers in better shape are common.
Examples with modest modifications that are easily
reversed, such as the "standard" controls in the drawer,
are much less expensive than unmolested sets.
But if you prefer the challenge, you'll need a different
manual. The AN/ARC-5 receivers are not wired the same
as the earlier SCR-274N and the diagrams are not compatible.
What does it say on the nomenclature tags of your sets?
That will help with finding the right diagrams.

73 Dave AB5S

p.s. If they are Aircraft Radio Corp. SCR-274N, they
are worth a big restoration effort.