[VintageLambo] Brake cylinder

I need new brake master and rather than pay $1,080 for a new one I want a resleeve. Fred Paroutaud pointed me to: KarpsRon Karphttp://www.resleeve.com Sierra Specialtyhttp://www.brakecylinder.com Whitepost Restorations http://www.whitepost.com/brake.html Any experience with any of these companies? I just spoke to Ron Karp who was very helpful on the phone. He quoted $50-70, plus $40 or new sealshe works in stainless rather than brass. Any thoughts appreciated... David Fox LP 400 Countach