Found these contacts on an American forum, unfortunately I am not sure if they are still valid
Optical Services Co.
Reticle Swaps. Boost on fixed-power scopes only. Call for model availability.
Issaquah, WA 98029
Reticle Swaps and boosting on certain scopes. Call for model availability.
1567 North Jude Ave.
Odessa, TX 79763
Reticle Swaps and Tucker spring modification.