[kiwi_steve]

<snip> they do not have to be mica at 455 KC precision ceramic will work fine. </snip>

Arran - just to clarify (for my own knowledge), when you say precision ceramic I assume you mean NP0 or some other tight temperature spec ceramic?  Tube radios get warm... and 'warm' changes the capacitance, albeit to a different degree with different cap types... which is one of the reasons I believe silver mica's are used - because they don't drift much with temperature change... 

I'm inclined to replace silver mica with silver mica, but NP0 ceramics (or equivalent) I believe are ok?  Or the old tubular ceramics?  I did try to find some NP0 caps down here in Hobbit land but they were 500 minimum order quantity... which was about 498 more than I needed.

Stunning radio by the way - we (to the best of my knowledge) never got those down here in NZ... might be something to import one day.

Cheers

Steve