If there is anyone in your immediate area who blues guns, you might see what he would charge to just blue the cylinder only. You could clean it up by hand yourself using #800 or finer sandpaper before bluing. The HPs had a matte finish when they left the factory anyway so a high polish is unnecessary. Bead blasting with fine media would also work OK. While correct stocks would be somewhat costly, you should be able to find some more presentable N-frame grips (not necessarily factory) at a reasonable price by keeping an eye on eBay listings.