Production variants are common (And I don't find them ugly, I find them functional).
Secondly, please read:
http://www.anime.net/macross/mecha/united_...vf19/index.html
The VF-19A looked virtually identical to the YF-19 prototype.
http://www.macrossworld.com/macross/toys/v...final_proto.htm
The VF-19 Kai is a variant of the VF-19A, and since the VF-19P is a variant of the Kai, it too, is a variant of the A-version. However, improvements were made to the VF-19 Kai compared to the VF-19A (rudders were merged with the wing, tail stablizers were pushed out farther, the 3-vernier block was replaced by the vernier slits, shoulders were streamlined, weapons bays were redesigned to accomodate a more versatile system).
The VF-19F/S version is a new variant mixed with the improvements of the VF-19 Kai. The VF-19 F/S models are optimized for space-use. However, this does not mean they cannot operate in atmosphere. Hence the redesigned wing and removal of the forward canards (replaced by the 3-verniers set).
Why don't they look the same? Because improvements always happen. The F/A-22 doesn't look exactly like the YF-22 because improvements were made over time.
Graham wrote up a lovely little article on the VF-19 way back which, as I see, is a completely feasible (not official mind you) piece of writing (See attached).
thanks for the info, but i have read the links you provided before, i was just wondering why did the "animators" changed the look? did they want something new to fit mac7?