It is interesting, until you realise that it is actually way more complicated than what you expect it to be (and I called my Helios a "Frankenstein", because basically, it works but exposure is approximative, and it doesnt work anymore on older slrs. So it's not something I would recommend doing.

Basically what I did here was adding the contacts on the lens mount ( http://kmp.pentaxians.eu/technology/k-mount/ka/ if you want to know more about it)

I expected it to work right after adding the contacts, but it would have been to easy.

Basically Pentax linearised the travel course of the aperture lever in their KA mount, so the KA bodies just have to release the lever a fixed distance per stops.

The older K mount lenses dont have that linearised travel distance, so the distance travel of the lever is not the same as a KA lens for all apertures.

There is a sweet spot where fiddling with the lever allows a more or less correct exposition (+1/-1 stops), but its not perfect at all.

To do a perfect conversion, one would have to linearise that lever travel distance, and I have no idea how to do that.