(slightly microphonic tube) 12AT7WA=CV455 Mullard NOS "curved D getter halo" copper grid posts 1959 perfect printing (8/9ma)

1 slightly microphonic tube as-is) 12AT7WA=CV455 Mullard NOS "curved D getter halo" copper grid posts 1959 (tk1-R9E) perfect printing 

8ma Gm=4600

9ma Gm=4750

microphonics is low, only noticeable when you tap on tube