Pentland are ime way better than Hendersons. A long time ago now to be fair but when Hendersons did my mmmbop he managed to get blasting media into the top coat so half the bike was gritty- the frame was full of it so I guess it just escaped while he was doing the coating. His solution was to hope I didn’t notice, I ended up just walking out with the frame and not paying. He knows how to do it and he can definitely do good work, he just couldn’t be arsed and hoped to get away with it. I’v used Pentland a bunch of times, they’re definitely a wee bit industrial but I’ve never had a complaint with the work.
R&O Refurbishment in Blackburn are really good too, he’s mostly a wheel guy but he’s done other parts for me including my trials frame. It was a dogs breakfast, previous owner had brush painted it then used a belt sander to “clean it off” so it was all scratches and weird flat surfaces, he spent ages on the prep to get it back looking good. He’s quite picky about colours, basically if he can’t guarantee he can get more in future he doesn’t want to use it, which can be a bit tricky but I’d go back to him for sure.