Heathkit AR-29 Stereo Amp Kit from 1971 - which capacitors to discard / replace?

[Miguel Angelo]

I have bought an "unbuilt" Heathkit AR-29 Stereo Amplifier from 1971 ( http://smg.photobucket.com/user/mhardy6647/media/AR-29.jpg.html ) on eBay. The previous owner probably opened back then and took the manual out to plan the build and never returned to the box to build or put the manual back.  I have not really looked into the box yet other than to confirm that the original manual was there. I have managed to get an used but complete manual on Ebay. The wood box that sold as a separate kit AE-19 (and was also probably purchased at that time) has not been found yet, but they are looking for it.

My question is considering that the kit is more than 50 years old, some of the capacitors may have not aged well and though they may not fail at the outset, their useful life may be affected. My limited knowledge would say that electrolytic capacitors would be more vulnerable and that  the low capacity ceramics would be basically impervious to time.

Should I replace the capacitors preemptively and if so which types? Any other concerns with such vintage kits?

[Lightages]

Replace every capacitor that is an electrolytic, tantalum, or any can type caps. Any film and ceramic types should be ok.