An interesting idea in theory, since one would essentially rebuild the circuit board, but likely hopeless in practice. Here's why.
Somewhere I think I posted this, but couldn't find it. This is distilled from my notes.
The PEC is a thick-film circuit, constructed on a steatite substrate which is silk-screened with conductive ink. The ink is made from metallic silver particles, some organic to thicken it, powdered silica, and a solvent to make it fluid. That ink is then applied using conventional silk screening (resist on a mesh allows ink to pass through) in a layer that is 0.01 to 0.06 inches wide and 0.003 inches thick. Silver is used because the trace will oxidize to some extent from all the heating/fusing cycles, but silver oxide and silver sulfide are conductive. (The black oxide, aka tarnish, on silver, including wafer switch contacts, is conductive.)
The ink-covered substrate is then fired at 1,400 degrees to fuse the metallic ink to the substrate. This evaporates the solvent (phase one), burns out the binder (phase two), and fuses the silver particles to the silica and the substrate. This creates a glassy conductive silver trace. That trace is sometimes copper plated to make it easier to solder with ordinary solder. This is a circuit board.
The components, which are tiny and SMD sized, are then applied and soldered on, along with the leads. The solder must have some percentage of silver, typically 3%. (Repairs to the tube Tek scopes use a similar percentage.)
Then the device is coated in phenolic, fired, labeled and shipped to distributors to begin the long process of corrupting HiFi equipment for decades.
So to rebuild this one would need to be able to clean off the phenolic, desolder all of the components from very thin (in every dimension) traces on a thin, brittle substrate, resolder the components, and repack.
Doable? I don't know I don't think the substrate would be damaged, and the trace should be hardy enough to survive desoldering. I don't know if cased components will fit in the available space on the substrate.
Those are just the issues I can think of off the top of my head. I'm certain there are more.
My conclusion is this is not worth doing. Particularly when point-to-point is not onerous and likely is easier to perform, likely has a lower failure rate, and will be far more amenable to testing and modification. Sam offered for sale in BT one of the common PECs present in the EICO and similar units. Beautiful boards. (No other connection than as a satisfied customer.)
If you decide to do this, please post some photos at each step. While I likely will never do it, I am very curious how it turns out.
