1219/1229/1229Q bases are the same. Early 1219 bases used a black inlay for the stripe in the front, later 1219's and 1229's used a black painted stripe, and they did away with the stripe altogether on the 1229Q bases. Some late 1229Q bases did have a 1/8" masonite bottom.
If the base says United Audio, it was made in the US for US sales, Noresco was the nameplate and distributor in Canada (and the bases were built better there), and Dual branded bases came from the Dual factory for the remaining areas. They were the best built, except for the hinky height adjustable base on the 1229.
Probably more than anyone wants to know.....