I used to be on a couple of forums on vintage stuff, but quit as I could not stand the bad info, and lack of knowledge by the list experts.  I have milsurp  and amphone as my only ones now. 

So here is my question since the carbon resistor thing was brought up.  I know that wirewounds should not be in tuned circuits unless the non-inductive style and those are a bit iffy, , but after that, with all the options on non wirewound we all use for prices I have seen as low as .007 cents each and $1 buys you 140 of them, is there a composition style more suited for each circuit?

The next is small value capacitors,  film, polystyrene, polypropylene, polyester,  MLCC ceramics.  I have used the most economical from a known manufacturer for most of my changeouts involving the old paper caps, and in audio interstage coupling, but again, is there a rule of thumb for picking and choosing a cap material based on circuit use, bypass, audio, etc?  Again, the audiophile sites have their opinions based on fidelity.  Prices for cap styles can swing greatly too, silver mice and stacked silver mica can cost you several dollars just for one, even on Amazon.

I have some old gear, especially my Heath TX1 that still has good and the original electrolytics in them, but from manf. info and actual work experience where we changed out every single aluminum electrolytic cap in power supplies on a 7 to 10 year cycle to maintain system reliability, how have the aluminum caps been holding out for everybody else.  The aluminum caps also age as they sit on the shelf and have a nominal 10 year life expectancy.

Charlie in NC