This is a post I made on another forum and I thought it might be of interest to some here.
Just FYI—a fairly complete list of commercial windvane manufacturers
Aries — Danish built. Not really suitable for smaller boats, as gear is heavy—35 kg or so. Servo Pendulum design
Beaufort — Very heavy French design for boats over 9m LOA. Servo Pendulum design
Cape Horn — French Canadian built, about $3,500-4,000. Servo Pendulum design
Fleming — Aussie built, Servo Pendulum design
Hydrovane — $4,000–5,000. Built in Vancouver, BC. Aux. Rudder design
Mr. Vane/Mr. Vee — Dutch based relative newcomer, fairly lightweight, has durability issues. Servo Pendulum design
Neptune — British built, Servo Pendulum design
Norvane — So. Calif. based. Fairly economical at $2000 or so. Servo Pendulum design
Sailomat — So. Calif. based. Servo Pendulum design
Scanmar — No. Calif. based mfg. of Monitor, Saye's Rig, and Auto-Helm windvane lines $3,000-5,000
South Atlantic — Argentina-based.
about 950 Euros, Servo Pendulum design
Voyager — Made in Ontario, CN. Servo Pendulum design
WindPilot — Fairly light Servo Pendulum design
hope this helps.