Don, isn't it a shame that the quality of an instrument does not necessarily reflect its value. I have (jokingly) moaned about tenors getting converted to 5 strings before (and there are people who would go the other way). Another example I have heard of is banjolins getting converted to ukele-banjos.

Please don't get me wrong, I have nothing against a musician having an instrument converted and to be honest, if I came accross a suitable 5 string Tubaphone and had money at the time, I would get it made into a tenor (saving the old neck) but I feel that it is a shame that market foreces and the popularity of an instrument at a given time/place can count more in financial/marketing terms than the quality of build.

Jon