Fenders are robust, but like anything else they need occasional maintenance. Her are a few photos of a silverface Twin Reverb I recently recapped.
I often take a moment to remove all the knobs and give the face a moist cleaning with a soft cloth. Most customers won’t notice, but we all know a clean car runs faster, yes? :o)
I prefer to use Sprague caps when I can find them. however I have been hearing rumours that the company was bought out and this series of products are or will be soon unavailable. That rumor jives with the drying up of vendors stocking these. It’s not the end of the world to use something else, but it’s nice to keep the american vibe intact if one can.
The earlier years of the siverface era still have 100-watt power supplies and do not yet have the ultralinear output circuit that the 135-watt models had. This makes them sound a bit better im my opinion – they break up sooner and have more natural harmonic products in the power stage. Ultralinear topology is great for hi-fi, as it really reduces certain distortions (think McIntosh amps) but is kind of out-of-place in a guitar amp, methinks. By the way, the ultralinear taps are easy to remove on any later Twin, but the power supply voltages will still be a bit stiff and therefore, loud and clean.