@lxdude post scriptum
The 28/3.5 Super-Multi-Coated Takumar and the 35/3.5 Super-Multi-Coated Takumar are superb lenses.
They were so good that Pentax used the same optical design, scaled-up, for their 55/3.5 and 75/4.5 lenses on the Pentax 6x7 system.
Thiis is somewhat comical, because both are petite, compact and light lenses on the M42 system.
However, when you "scale up" the 28/3.5 to a 55/3.5 (that covers 6x7), you end up with a lens that weights 920g and has a 100mm filter diameter(!)
The 35/3.5 scaled up to a 75/4.5 of 600g and 82mm filter size. The optical system of this lens was so good that Pentax basically produced the same lens (optically-wise) from 1969 until the 1990s.
The 200/4 is more or less a scaled-up 135/3.5 SMCT, and I'm sure other lenses in the 6x7 lineup also have some relationship to M42 lenses.