The new adjusted "tariff" price is now $6K for your PL. Yikes! May as well spend a little more for something like ARC, VAC, etc.
I would enjoy it as is with NOS tubes also in the rectifier slots-pricey but you already know that.
If it were an integrated amp, the coupling caps can make an audible "improvement."
No way you'll get a schematic, unless you had an "inside connection" with an authorized service guy that has access to PL info.
Do fancy boutique input/speaker jacks REALLY improve SQ? 🤔
Maybe with the pedigree solder and Nordost Odin cable?