At the risk of starting another club, we shoud have an 85mm club.
I had given up on finding an 85 so I went out and bought the vivitar 85mm F1.4 (KA mount), 3 weeks later I happened onto a super tak 85 F1.9 for a price that I have never seen one at before ( or after) about 40% lower than the typical selling price.
There was only one solution. I bought it.
The problem is, up until that time I had a firm grasp on LBA, only buying lenses faster than what I already had. But with the 85 F1.9, an smc tak 35 F2 and a vivitar 28 F2.5, I began to think M42 kit.
My adaptor resides almost perminantly in my K10D these days
With these 3 lenses as a basis, I have since put an M42 adaptor on my tamron 24mm F2.5, added a super tak 50mm F1.4, an SMC tak 50mm Macro, a helios 58mm F2, a tele lentar preset 135 F2.8, a preset tak 200 F3.5 and an SMC tak 135 F3.5.
I still need (maybe) something at 100mm but I do have 2 different 2x M42 TC's so I already have 100mm F2.8 with a TC on the 50mm.