HI: Thank you for that Kev.yes mine are the same values.except in a block bar or thick biscuit .0005 and .002 .
If it were up to me then I would keep it as is,because if you put valves in it you may then need to re- calibrate it and then its not an original as you will have to disturbed those locked trimmers.I must admit that is hard to do.I don't think paul Stenning above has the circuit ,but I got mine from the ( Valvepage.com)the only prob is there aint no components marked on the circuit.so I had to make up my own numbers and put in the values and it works fine now.thanks again.
Gezza
ps: you would also have to change those to caps in the 400c/s oscillator IE: O.O5 450V + O.O3 350V papers and maybe the two 4uf ht caps.