Rgurney: Correct. The mesh plate wouldn't match amp design/circuitry. That's most likely why so many 300B's fail - not matched for amps.
Phaelon: Hopefully I can recall what the NOS WE sounded like. It's been a few months, plus I'll have new speakers. I think the EML 300B will be satisfying enough based on feedback. It looks good too (resembles WE more then others). In the end all that matters is whether or not I enjoy the sound from my system.
I would have tried the Shuguang Treasure but timing and shipping from Canada.... plus they didn't have Grade A in stock. Considered Grade B ($375). That's how much I'd like to pay for these 300B knock-offs. I almost bought current WE production but the asking prices are ridiculous. I'd rather buy used NOS.