This is an Oil Temperature gauge type A-24. Still visible on the glass, is the green markings indicating good operating zones. These markings were either painted on, or used a green strip and adhesive. This gauge appears to have used the adhesive method, as evidenced by the yellow tarnish surrounding the marks.
This particular gauge seems to have been produced for a Waco C-62 (WC-62) transport plane in 1943. No C-62s were ever built, however the serial number matches the serial numbers designated for the C-62 production. It's serial number is 42-35785, and the numbers reserved for the Waco C-62 spanned from 42-35584 to 42-35823. This places it directly in the middle.
Most likely, this gauge was used as a replacement part for a B-17, B-24, or one of the other aircraft which employed the Type A-24. Because if its wear, it was most likely installed and used during the war.