Here's the shocks now and a picture of my 500

If your springs look good do it. Rust developes where it's chipped off. Then....
Rocks & roost shrapnel chip the springs PC which led to my short springs breaking. The springs aren't cheap!
Rebuilding was costlier than the original dealer cost $217 back in '87
if you powder, use a flex agent. they will chip though, so prep the spring good.
and rebuild a works shock is cheap, but the to respring is costly.
Did you find out the spring rate yet? What if these are for a 300 lb rider?
Still got to be better then stock banshee shocks.
I just got them on Friday and was too busy messing with the gixer 1000 to mic them. I'm definitely going to mic them and find out the weight setup before I go powder coating but I think I'll be alright.