Do you think it would have lasted under normal circumstances? The one on the bike now has a minor bubble but still looks fairly nice. I obtained a new one a year or so ago in anticipation of replacement (when it finally gets bad enough). But I would consider painting one with "chrome" paint if if seems to be durable enough.
Yes, the urethane paint held up. My box fan was not circulating around the alternator enough to cool it during an extended carb sync and the ABS went to hell. The fan was only directed towards the radiator.
I can only vouch for the heat durability of a urethane paint & clear-coat.