I looked at your pictures and think you are using single WL springs, WR tappet guides, and spring covers?
Steve Hartley, 37ULH on this forum is making single valve springs for the WL/WR that allow use of very high lift cams without coil bind, and have seat and open pressures which are similar to the dual KR springs. Most of the WR road racers in the US are using these springs with roller cams.
I have personaly measured the pressures and deflections on these springs along with the dual KR springs, and some WR springs which were made by S&S for Fred Pettis.
Email me and I can send you PDF's of my results.
Also the dual KR springs are the same as used on the Sprints, While these are unavailable. R&D Spring in Calif. makes replacements and I believe they are the same as used on 650/750 Triumphs.