I have an William's FP-AG-TK rear aperture (peep) sighthttps://www.airgunsofarizona.com/WilliamsGunSights.html
on a HW 80 that I need to be able to lower a little more then currently possible. It is a very simple job but can easily be screwed up. Just want to remove .050 thousandths from base of aperture carrier with surface area of less then 1/2 square inch total.
If you have a milling machine and are a careful machinist this would be a simple job. I'm will to pay for the service.
Please email me if interested and I will give you the details.