So we tried opening the PST to verify the prism was perpendicular to both the etalon and eyepiece, but Coronado clearly does not use hardened steel for their screws. A few very gentle attempts and the hex head is reamed out. The rest of the screws came out fine but the lid (side) is very firmly still attached. So now I'm stuck, I could close it up and say it is as good as it is (short of sending a new scope to Coronado for an expensive check up) or I can try drilling. I expect I can remove the shavings without a problem but I fear it would reduce future options.