I think it's important to point out that these wheels in question are more than likely
not "split rims" and as such do not deserve the bad name/reputation that goes along with the term "split rim"
In fact they are likely lock ring wheels, either two or probably three piece. This wheel design is still manufactured today and is well accepted, often used on heavy equipment and trucks.
I'm not saying that switching to tubeless wheels is a bad idea, it's what I'd do in this case.
But don't give the folks that like and want to use the stock lock ring wheels the idea that they "have to" get rid of them, this is not the case, and not a myth worth perpetuating.
Again, check the tech tip for some info on the different types of wheels.
http://www.stovebolt.com/techtips/wheels/Grigg