It seems to me that the basic layout of the trumpet has not changed in 130 years, we have the modern piston valve trumpet originated in the1890s I think and refined to the pre WW2 Besson that most modern instruments are based on, and the European rotary design.
R and D and retooling are a very expensive process for a company making a product that they have a market for with no guarantee of acceptance.
Lots of variables to the basic design, light and heavy weight, different leadpipe and bell tapers, straight or stepped bores, no and position of braces, diameter of bellrim etc but all of the common layout.
This is one of the reasons I have put my money up for a Jerome Wiss 6/20 trumpet, he has gone outside the conventional design, I will not have it until later in the year, looking forward to it and will write an extensive report on it.
Regards, Stuart.