[codefox1]

I have an little box on my workshop bench which inserts a common light dimmer into the circuit. I sometimes use this to control the heat for a throwaway soldering pencil (like from the 99 cents store) to just hot enough to melt the tar in those bakelite capacitors. That way it's a little easier to get all the crap and what ever is left of the original capacitor out without a lot of fumes and smoke. Sometimes, it's just a matter of digging all the stuff out with a scalpel or box cutter, other times the tar is real hard. There is always at leasts one crack, which has let moisture in and ruined the component inside. In any case, for authenticity, and ease of assembly, you will want to get the old material out without destroying the bakelite case, put new caps inside (there will always be enough room, use 600 or 630 volt modern orange drops or equivalent.) There is cross reference available on this forum to double check values. Of course some of these bakelite blocks have nothing connected internally, and are only used as tie points. That's why it is probably better to retain them, so you do not have to resort to adding new terminal strips, or tacking things together without any physical support. As suggested many times before by persons with more experience than me, it is unnecessary to attempt to fill the bakelite "tombs" with wax or anything else, as the modern components have good enough enteric coatings to survive for several decades, and will probably be readily identifiable after that, should the set again need service.

BTW. the light dimmer trick can also be used to stupid check just about anything, or slow down a drill to a crawl. The worst that can happen is that the dimmer craps out. Then you put in another one. Not a replacement for a variac by any means, and will not be friendly to any solid state devices, but just another little old school bench stunt.