Nobody makes a proper clamp so I had to build one myself. It has been improved since these pictures were taken but the key features are the same.
Two main features: the thick washer that fits over the spindle, and the under side of the clamp is dished out. Really need to take more and better pictures because this subject keeps coming up.
Dont know where you've been for the past 40 years, but reflex style clamps/washers have been around since the 80's - SOTA, Goldmund and others. My Japanese turntable built in 1971 had a massive dished weight as standard along with a selection of washers of verying thickness to optimise for each record.
The big joke with many ultra expensive record weights like the Dalby is that they have a flat bottom and do absolutely nothing for slightly warped records. The biggest laugh for me was the stillpoints which I tried - all it did was muddy the sound.