Mark's right
The Catalina 25/250/Capri association has a lot of helpful people. Check out our site. In the meantime, try Catalina Direct -- http://catalinadirect.com/ . You can also contact Catalina Yachts parts department for things. Particularly the seat cushions. They're pretty responsive to phone calls but their website leaves a lot to be desired. Can't even find the parts department there. If you have a wind speed indicator, that was likely an after market addition, not standard on a 250. You might have to check with the manufacturer of the gauge. As to the windvane, they're available at most chandleries. West Marine, Defender http://www.defender.com/ (great service -- no sales tax) are two that I've purchased from.