Marantz Model 2 Amp Schematics...1950's?

I have recently acquired a pair of rare Marantz Model 2 mono tube amps and would like to bring them to a local hifi repair shop for a tuneup. I would feel much better having the schematics to avoid any problems. Any thoughts as to where I may find these? Thank You.
If the marantz working fine, don't touch it!
You local hifi repair shop is not experienced to handle this gems. Don't let him touch it! Any mod. to the marantz or any parts changed will alter the sound and your investment will go down to drain! "Save the original parts", working or not!
Try if you haven't already. You may find some info there. Good Luck!