That I have to disagree with. There were PE 100 macro's. KEH has some for sale right now. They also have a couple of E's. Tamron says the MC designation was dropped in favor of E, though I sure haven't seen many lenses marked "E".The other lenses have no direct PE equivalent...100 Macro MC, 200MC, 500MC
I suspect but don't know that they are the same, as the 105mm 4.5 PE macro was coming down the pike.
There is definitely a PE 200. It also has a long close focus compared to the 180.
I have not heard of a 500MC, though they sold both the 500 f/8 PE and 500 f/8 EII, which are very different lenses, with the PE much larger and twice the weight, and much more complex optically.