From 1953 a very good vintage year for W.E. Tubes!
Same code of production.
Beautifully Clean. One carton has some scratches.
Tested as 37, 32 over 25 from TV-7 tester. Results are for Reference only. All testers are different. Yours can be different.
Easily Best choice to drive the 300A 300B, 252A , 350A, 350B Power Amplifier tubes.