It would likely be a Furlex 200, but you better ID the actual unit on the boat as on a 30 year old boat it could have been replaced by a PO. Depending on the problem rebuilding the unit may be just as costly as replacing with a new one. Try lubricating the lower bearing assembly as well as the halyard swivel. Wash the assembly with a pressurized soap and water solution and rinse off with a hose, allow it to dry and then lubricate. If the bearings are shot then removal of the unit would be necessary. At this point it would be advisable to expose the fore stay for inspection and install the rebuild or replacement unit. If you do not have experience installing these units I would recommend you engage the services of a professional rigger.