It’s easier to remove the leadscrew while dismantling the carriage and apron, which requires removing the cover from the control box containing all the switches & knobs. Come to find out the “cover” actually holds all the gadgetry onto the headstock:

I want to replace the Power indicator with something visible in normal shop light; judging from the connectors and overall brightness, it’s a neon bulb inside a green housing.
Anyhow, the four screws holding cover to the headstock weren’t identical:

I thought the oddball screw was deliberate, perhaps fastening that corner to a plastic frame of some sort, but it turned out to be a quick fix for a boogered tap job:

A bag of 4 mm knurled brass inserts will arrive in a while, after which I’ll drill out all four holes and epoxy inserts in their place. Might have to use stainless hardware, just for nice…