Here's a wonderful period correct Silca tire pressure guage.
http://www.flickr.com/
Perfect condition, not a mark on it. True bourdon - tube mechanism (like a barometer).
A delight to use. Has been in my collection since I bought it from Spence Wolf in 1975.
I replaced the grommet a couple years ago (same as the frame pump)
Drive it home today for 80 bucks shipped CONUS. Paypal only.
Mark Petry
Bainbridge Island, WA