I have left them well alone for years, but its got to a point where I have gone out and bought a set to replce them because my back-up MTB deserves better than these as they currently are.
Now is the time to open them up and (hopefully) learn to service suspension forks and (worst case) get to a point where I can list them on ebay accurately.
Without opening them up I can only advertise them as “don’t feel great, not been serviced for years, quite possibly f-ed”. Hopefully I can get a touch more for them advertising the specific problems as opposed to not knowing anything. And if they are servicable then that’ll be a great bonus!
I’ve done alright considering I bought them as part of a full bike for £150, that I used for a few years then split, sold parts etc etc!