I don't know about current Turnbull Open Range revolvers but I have two of the Turnbull Cowboy Classic USFA guns, which preceded the Open Range guns. Neither of mine feel like they have had any action work done on them. It depends on what you mean by "need". There's a lot of things I want but do not need. I have guns I've never fired, that I've had action jobs done on-go figure.
I do agree with the idea of trying a spring kit first. I recently bought and antiqued a Uberti Hombre . I put a Wolff spring kit in it, simple to do, and it did make a big difference. When I do get action work, I usually use Bob James,
www.jamesguns.comHe is one of the best at it, if not THE best and is a super nice individual. Problem with sending guns off these days is the postage both ways usually exceeds the cost of the action job.