Update 1: After a lot of measuring, got the new Hipshot bridge drilled & installed. Realized that the dot inlays on the fretboard are NOT perfectly centered, so they’re useless for finding a centerline.
Used a simpler method of bringing the saddles to the 3/4 mark on the bridge, drawing “extension lines” down from the sides of the neck, measuring 34” from the nut and crossing the extension lines with a perpendicular line, measuring that to find the center point, then placing the bridge. I aligned the bridge’s center mounting hole on the intersection, then marked the other two mounting screw holes.
To be extra sure, I dug out our Ryobi vacuum stick-on laser level, stuck it to the HVAC duct (low ceiling basement!) and pointed it downward. Worked fairly well!
Bridge in place:
I used a couple of drops of iFixit adhesive remover to get the last bits of old pickup foam residue out of the pickup cavities. I noticed that both cavities actually had what looked like thin plastic plates stuck to the bottom - maybe this was the old “shielding?”
Detached the grounding cables and began coating the cavities with the MG Supershield nickel paint. I painted on two coats, with recommended drying time between. Should be cured by tomorrow afternoon.
That said: REALLY read the instructions. I thought the solvent VOCs would be fine indoors for the small amount I was applying (plus running a room-size air purifier on my desk next to the work area), but this stuff is capital-S STRONG.
Absolutely find a well-ventilated outdoor space to use while applying it and ideally to let it cure overnight.
Also: Wear proper PPE (a rated respirator, safety glasses, and solvent resistant gloves); apply a little at a time to avoid drips; and be sure to tape around the edges of the cavities to avoid potential damage to the finish.
I was originally going to try this paint in the electronics cavity too, but after this, I’m going back to copper foil.