[Arran]

 Probably the best way to replace one of those that's warped, shrunk, and cracked, is to make a replacement out of wood.  I seem to recall that someone on here did that with a table set that had the same sort of escutcheon. Alternatively one could make one out of sheet plastic stock, such as ABS plastic, by cutting out the pieces and gluing them together. On my 42-327 cabinet, with a similar dial placement, the escutcheon was made out of wood from the factory, and painted black, and it looks very similar to that plastic one.
Regards
Arran