Good morning, Per A.
You are successful: Welcome to the group. And, you need to do it only once.
Your collection of Asahi/Honeywell Pentax M42 mount cameras far exceeds mine. There is only one original simple Honeywell SPOTMATIC here, along with a Vivitar 250/SL and a Vivitar 450/SLD, and also a KMZ Zenit-TTL also. Just recently I also found a Tamron Type PZ-150Au f:6.9/200-500mm zoom lens Adapt-A-Matic with an M42 mount that can go onto all of them. Now there is a range of lenses from reasonable wide angle to fairly long telephoto to fit the M42 Mount cameras. Using cameras that expect the photographer to be a participant in the photographic process is a very satisfying way to work with film.
Enjoy;
Ralph, Latte Land, Washington