Nick - Just a little different track thought process than trying to restore what you have offered here, considering how much you have going on from the water damaged cluster.
What about going with a restoration kit, like this
Classy Chev USA 1941-46 Kit? Looks like it gives you everything but the gauge mounting panel and individual gauges for what looks like a fairly reasonable price.
Or an alternative like this
Used '41-'46 unit, for a pretty reasonable price? It looks significantly better condition wise, and would likely save you some angst and hours of effort to give you an original instrument cluster.
John - What "paint" did you use to refresh the gauge mounting panel? I've searched through the old threads and haven't found anything specific that identifies a suitable matching color.
