[LargeFormat] Aerial camera

[john frost]

I just bought this great big box. Inside, the somewhat smaller box sez 
"KEYSTONE
MANUFACTURING CO.
BOSTON, MASS. USA

CAMERA, AIRCRAFT - TYPE F8
FOCAL LENGTH 15 INCHES
CONTRACT NO. N-288-S10913
SERIAL NO. 894"

In the front is a #12 minus blue filter on a Wollensak 15" f 5.6
telephoto (yellow dot).

I took the back off, the platen and glass appear to be good. I cranked
the big knob, and the shutter wound up ok, but the little button that I
thought was the release is really the film counter reset knob. It has a
hole in the end - does something go into there to trip the shutter?
There is a thumb lever near the handle on the body that goes
'flap-flap', is that for shutter speed control??

The film cassette sez 7 inch by 18 feet, KODAK TRI-X AERIAL RECON. 

Was $30 reasonable ?
How do I trip the shutter, and set shutter speeds?

It weighs 17 lb. empty.

The glass film plate is 5x7 inches, does anyone have a cut film holder
to fit??

Should I bring it to the workshop?

John (:>)