Im rebuilding the caliper on my 71 CB500 and would like to know at what point to give up on saving the piston. I was able to finally get it out with compressed air but there are some small nicks on top edge of it. I could probably sand down any imperfections but am worried it will leak or destroy the new seal. An OEM piston is $100+ from my local dealer. Any sources for aftermarket pistons or compatibility with other models? I did some searching and found KL products but no listings specifically for my bike. Any advice appreciated.