[falcon123]

i'll answer my own question as i just found it on the web. there were two types of mica capacitors, silver mica and "clamped". clamped was two sheets of mica as it says ,clamped together and encased. they are reported to be not as stable or as accurate with regard to tolerance. just looking at it, if i was doing the set i probably just replace them with modern silver micas. mostly, as i dont know how well they hold up over the years as opposed to silver mica. seems like its prudent to eliminate any failure related item if indeed they are