Thanks for all the info. I'll check on the single stage for the firewall and underhood, from my supplier.

But I guess I have a lot of "under the hood" bits to move now. Blowing apart them main body is no big deal (a few bolts). The vehicle is a Hummer (a real one) and they are made too be dismantled in the field. The engine compartment is a little work though as it has air compressors for the tires, and all kinds of do-dads mounted on or in front of the firewall (plus padding for noise) Easy to work on the bits, tough to totally remove.

My guess is you would use a little air-brush in these places.

Thanks,

Scott
Restoring '93 Hummer
in the Desert of Saudi Arabia