@ Monkeyface: Hmm interesting... I don't have 20 watt in the F range, I have the 20 watt version in the normal version, do you have them??? maybe we can arrange someting...
Maybe someone else have the 40 watts version??
Just let me know your adress and I'll send you an assortment of some special vintage tubes including the TLF 20W34 and ...55! I got plenty of them but no space! Just a few specific tubes i'll keep untouched untill I really need to... ;-)