http://www.vintage-mustang.com/topic...ionsblurb.html

Parking brake warning lamp was available in '65 ( Including 64 1/2 models which is what your picture Part # shows )

Seatbelt warning came in in '66. I had a '67 with it on. They seem to be more common in convertibles, with reason I guess.

http://www.fomoco.com/1965-1966-mustang-parts.shtml

Stu