RCA, GE, Russian, Chinese, Japanese 6L6GC's. Measured on a Hickok 6000A. Negative for shorts/gas and passed the life test. 5000 is the theoretical new tube on this tester. 2600 or lower is reject level. All prices shown obo. (I also have 3 pair of British made Mullard EL34's that I'll be listing shortly)
Tube (L to R) Measures Price
1st photo: Conn and Baldwin logo RCA Blackplates. 4900/5200 ($160)
RCA and RCA silver logo RCA Blackplates. 5000/5050 ($175)

2nd photo: Baldwin and Conn logo RCA Blackplates. 4200/4600 ($125)
RCA and no logo RCA Blackplates. 5000/5000 ($175)

3rd photo: Fender Groove Tubes labled Chinese 5300/5700 ($60)
Groove Tubes labled Russian. Dual Saucer Getters 4900/4900 ($60)

4th photo: Lafayette labled RCA Blackplate 4000 ($50)
Tram Labled GE 4200 ($35)
Seeburg Labled RCA Blackplate Dual Bottom Getters 5400 ($80)
ITT labled Japan Blackplate 5400 ($50)