I'm not sure if the leupold custom shop can boost power, but do a search here for "optical booster" and you will find some threads about an optical booster that attaches to your scope and boosts power, the brand name of the product escapes me at the moment but they have advertised here on this site in the past.
The booster is made by Gunsmith Gene Davis in Ohio and called "Bulzeye". I had a 3x when they first came out; put it on my Leupold 36x and Weaver 36 x target scopes and the image blurred after 300 yards. Sent it back for a refund.
Do a search for Bill Ackerman in New Mexico; he does that work on some scopes.