You know, I should have fabricated my own washer to give me something bigger like yours. But it does what it's supposed to. The good thing is the springs on the second (parts) camera I have are stronger and should help on the 4x5.
I'm working on a method to add a geared lensboard tilt mechanism. something that you can adjust more delicately. I'm first going to construct a "dummy" set-up to try first. If it works I'll pm you the design.
Similar to what the agfa's have but adaptable (I think) to the Korona without
taking the front standard assembly apart and simple hardware parts. All supposition at this point.
I like bringing something back to life (so to speak), to continue it's use, wondering who has owned it over the years, what photographs they taken, where it's been.