I have for sale a tachometer. The label on the bottom says it is a Rochester
Gauges Inc. of Texas, Model number 3310-00031. The green arc goes from 500
to the red line at 2700. I will try to email a picture on request. If
interested please let me know. I do not know it's value as I have had it for
some time as a spare and have not used it. I assume it works, but no
guarantees. I recently sold my airplane and have no use for it. A reasonable
offer will be accepted.
Thanks, Fred Z.