Thank you all (I'm from Kentucky) for your participation here and via PMs. Here is a progress overview.
Indeed a high priority is to avert losses from aging electrolytic caps. New work will have ALL film caps for indefinite product life.
In broad overview, all series signal path caps are ClarityCap CSA-630 volt. They have excellent technical and sonic performance at justifiable prices. I am bypassing with the custom 1uF styrene that Thiel had made from best German film, now defunct. We will salvage your old ones.
I will be double-bypassing with 1% fractional value MultiCap styrenes. Thiel CS2, 3 and 3.5 used this trick with MultiCap's predecessor. Jim dropped out as of the 2.2. I'm back in for the quicker and quieter leading edge transient at what I judge as justifiable cost for this upgrade scenario.
Shunts to ground in Thiels (pre 3.7 and 2.7) are electrolytics bypassed via that 1uF styrene. I am going with a custom ClarityCap polypropylene having all CSA factors but with a 160 volt film for manageable form factor and cost.
As beetle has mentioned, all resistors are being replaced with Mills MRA-12, an excellent and cost-effective solution.
Note that I am aware that some might want to go farther afield with cost no object components and others may balk at the significant cost of my choices. My vision is to find affordable solutions that reach the next performance / cost plateau. This project is larger than may be obvious. This relatively major redrawing of the rules will require re-voicing both via measurements and listening. Beetle's 2.4s and my PowerPoints are the first line of that work. Our custom parts will arrive early June, when we'll engage the core work and begin substantive feedback regarding our judgements to date.