Looking for a spare pair of 3-400's or 8163's for a L-4 amplifier. No, I don't want to cram 3-500's in there. Prefer new (what'ya mean they don't make 'em anymore) or NOS if possible, used tubes in excellent condition (low filament life, like new) considered. I don't want much, do I? ;-) Thanks. 73, Russ WB8ZCC