Stupid me. I attempted to clean the mirror without dissassembling the rear, and out came what I believe was the X axis Galvano mirror. It appears to have been epoxied into place and snapped cleanly along the edge.
Unfortunately some of the links there are dead and I’m not sure if the galvo components can still be found anywhere on the market. But at least it’s a starting point.
This thread might also be interesting if you decide to attempt a repair:
Is your laser in good condition? Any issues with prints before you tried cleaning? I might be interested in the “for parts” printer, or just the laser.
I empathize with your situation. The original laser in my beloved Form 1+ died ages ago. I attempted a repair but wound up cracking the lens. A kind forum user even sent me an old laser they had kicking around from their mothballed printer, but unfortunately it didn’t work. After several months I finally got a Peopoly laser and it works well, but the power doesn’t quite match that of the original Formlabs lasers and it’s best used only with OpenFL. I’d be keen to obtain a working original laser.