I did like the Mk4, it was an old school fixed 10x with .25 MOA adjustments but it worked well. Then the OCD bug kicked in and I had to track down the repro base and scope. Now after selling I’m working on #2.
The Redfield looks good and obviously tracks well on yours so stay the course I think, unless you want something more versatile. To be honest, as l noted before even the MST is a very single use scope that doesn’t cross over as well to target or field precision work on really small targets, but looks at home on the rifle. It showed some shortcomings in the single precision match I fired it in prior to selling it. But I did like it for what it was if that makes any sense.
What chamber did you opt for in your rifle? Maybe time to try some 77 grain or 80 grain loads in the future?