Many photographers keep one of these Wollensak Sunshade and Filter
Adaptors on their Graflex Speed Graphic, Crown Graphic, Bush Pressman,
or other press camera. It acts as a lenshood, and holds filters, but
it engages the f-stop indicator on the lens so that by turning the
lenshood, you change the f-stop. (See the photos on the auction site)
This device is designed for lenses such as the Kodak Ektar, Wollensak
Optar, etc. which have a barrel diameter of about 36 to 39mm. It
attaches to the lens with two thumbscrews. This is a very
clean-looking item in very good condition its original box.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330016039055