peeps and TC

The Thompson Center Impact 50 cal purchased last month is a great shooter.
With the factory sights we can produce 4 inch groups at 100 yards and hit 24 inch metal at 235 yards with consistancy.

I want to change the rear sight to a peep mounted in a set of scope mounting holes near the back. This will remove the mid barrel notched rear and give a longer sight radius and better target acqusition.

The first effort was a Williams WGRS peep that is easy to see but there is not enough elevation adjustment to raise the bullet more than 6 inches low at 50 yards.

Took it by WWG and they recommended trying to find a TC rear sight that might work.

Do any of you experienced shooters have any ideas?

Maybe a mounting plate under the WGRS?