1960s George Philbrick operational amplifiers for "Computor" devices that GAP made. This pair boasts serial numbers that are only 6 digits apart; the modules may be samples or NOS, or may have been pulled used from equipment in the 1960s. Apparently late 1964 mfg. date. I believe these are top-spec Siemens ECC83 valves (though perhaps Telefunken?) alongside RCA 6BN8A's. 

The tubes were custom screened for Philbrick. The octal-base enclosures are in very good condition for age. These are interesting units, whether you just want the German 12AX7s for their hallowed audio quality, or the entire bits of kit for your Sixties computing collection - up to you! no reserve!

THANK YOU for looking!