Anyone have a good resource on repairing vintage Hehr windows?

[Jakattack]

I need help finding more information on how to work on these old windows. I want to make sure I don't mess up these windows knowing how hard they are to come by.

I haven't been able to find a good thread on this or maybe I'm searching the wrong things. If you know of a thread that does a good job going through the windows and how to bring them back to their former glory I would really appreciate it if you posted a link in here!!

Thanks for looking!