Coronado cranksets were/are made by
Thun. They turn up regularly here in Europe, mostly in swaged form on lower level bikes. They were probably cheap.
Having said that, the OP's set looks nicer than any I have seen (one piece, is it?) and the sets I have feel very, very light, so I'm holding on to them for a weight weenie build.
As for the chainring replacement, I would just take any pair of decent 130 BCD rings with the required tooth count, and not expect any problem other than *maybe* having to adjust the limit screws on the derailleurs. The only time I ever ran into trouble was with chainrings that were made for 1/8th chain, and I don't think those ever came in 130 BCD.