I have 'inherited' a Bilora tripod that's about 30-40 years old, at a guess. It's in decent nick but some of the head motion feels a bit 'sticky'.
Is it possible to 'service' tripods, or should I just consign it to the recycling?
The key question is, I think: Is the stickiness caused by dirt/grime or corrosion/breakage?
In either case, I believe the answer is yes, it can be serviced, but in the former you just need disassembly and cleaning while the latter may require replacement parts, which are perhaps tricky to find (but check eBay).
If it's just the head that's not working, you can probably replace that part and keep the legs.
Unless you have too many of them already, dodgy tripods still make fine speedlight or reflector stands, so do reconsider recycling them.