Have an older Harry E Hanson. Tester here. I did not try to use it. Did not open the Back. Looks pretty good.
Vintage Harvey E. Hanson Engine Vacuum Tester Vintage No.6 Gauge
Vintage Harvey E. Hanson Co. TL-324 Power Timing Light Chrome Paw Paw Michigan
Vintage Harvey E. Hanson Compression Tester Model 5 w/ Original Box (1963)
Vintage Harvey E. Hanson Dwell Tachometer Tester
Vintage Compression Tester Model No. 5 Harvey E. Hanson CO. Paw Paw, Mich. USA
Vintage USA HARVEY E. HANSON CO. MODEL 24 Chrome Power Timing Light Michigan
