My guess is if there is a "spray on-wash off" agent that truckers use it is good for cleaning an already clean or polished surface, or a surface that has some kind of clear coat on it.
If in doubt, go to the local big rig dealer or servicing center and ask.
Also, ask local EAA guys if anyone in town has a NMF plane and get advice.
My guess is
the only way you'll get rid of years of tarnish on metal is a paste and then buff job.I have a car with lots of brass on it....no such thing as a free lunch.

Call the Meguires wax people. They have a customer service center to answer questions like yours. IIRC, they helped, or did or contracted for, the polish job on the Lyons B-17.
They can point you in the right direction.
A friend uses Mothers aluminum polish with good results.
As far as budget goes...ask Meguires if they could give you a discount. You might have to write a letter or something, the worst they can do is say "no".
Also, if it's a community service, ask local auto parts stores for donations of the polish or buffing pads/machines. Car clubs usually hit them up for door prizes and awards for shows, they're used to it. Again the worst they can do is say "no".
You might ask a local car club for help, most of their members will have buffers and many like to do service work like this.
The local EAA chapter or a JROTC unit might help too.