He might make them for King valves, but the design sold by Meinlschmidt is only for the MW Big Valve piston set.
The valves in the old 2341 and 2141 are interchangeable, I think, and I think they are also interchangeable with the current 2341. So, if Martin sells MAW valves for the King piston casing block they *should* fit your tuba.
Note that MAW valves remove part of the restrictions imposed by the curlicue nature of the ports and knuckles through a piston set. They do not make anything *better* but make them *different*. Usually, these differences are perceived as improvements, but I know of a few folks who hated the changes made by MAW valves and promptly sold them.
Also, the whole "point of diminishing returns" idea comes into play here, as a set of four MAW pistons will set you back enough that you could have bought another 1241. They are not cheap at all, and such a huge expense will not be something you can expect to recoup if you sell the tuba later. Upgrades to cars do not increase the resale value in most cases, and that applies here, too, in most cases.
Further, your casings could leak around the ports, due to wear from the age of a 1241. This is not a new tuba, and wear can actually be worse to yellow brass casings than to nickel-plated pistons over the long haul. In all honesty, I would have your valves checked for leakage before dropping a lot of cash on fancy valves that may not do what they are supposed to do because the casings you dropped them into are shot. So make sure to investigate that first to save you some potential disappointment or frustration.
Personally, I like the MAW valves and plan on looking into a set for my Nirschl-made pistons. I am pleased with them on this 2165 I have sitting here, and I think they would do some good for my Holton 335 (which has a Nirschl valve set on it). But before I do that I have to carefully check to see if my piston set leaks. If it does, are the casings at fault or the pistons? I don't plan to drop upwards of $1500 on a set of custom MAW valves if the casings leak. (I think I'm good on this, but it is a lot of money, so I need to be certain.)
Keep in mind that Mr. Wilk is the only person who can answer your questions 100% accurately. (He is not known for his phone etiquette. If you call him, be prepared for curt answers. Have everything you want to ask him written down. Do not try to chew the fat with him. He does not enjoy doing things on the phone unless it is an actual sale. He is a nice man, but he prefers to not work via the telephone.)
Since this is the situation, any hard information from him would be something worth sharing in a post here, both for now and for the archives.
Good luck!
), but - once installed - I now have closer tolerances, and ( 
) can now pretend that the instrument plays better than before.
