They’re Rockshox Revelations 110-140mm Air U-Turn from 2008/9. They’ve barely been used over the last 3-4 years since I turned stiffback roadie and have been serviced once since I bought them.
They’re shooting through the travel and bottoming out without a huge amount of resistance, but I don’t think it’s too little positive air in as if I just sit on them the sag’s about 15mm which is about right.
Do they just need a service? Any ideas of anything else I can do to sort them?

well step 1 would be actually get a shock pump on and check the pressures…

if pressures are fine then get em apart and have a look

Sag should be measured stood up, as if you were about to attack a trail feature; not sat down.