Glenn & Steve, the rings shown are Kimbers, the levers are hidden on the opposite side. The rings are the low height, I used the medium height on my other walls with no problems. Later I'll try to show a pic of my low wall K-Hornet with a 3x-9xEFR Leupold and I'll measure the pertinent dimension as well. I find the Kimber or Warne Premier rings to be some of the most graceful, with the early Kimbers being the shapeliest IMO.
I've seen the wall hammer spurs bent down slightly for thummb clearance, and you can gain some room that way. Brent's superb back-bored low wall is done that way and it worked well, also I have done the same successfully. Too much bend, however, will cause interference with the spur's rear end so go easy here.
More later, regards, Joe