Lee is working on three of my guns at present. He fitted a Kreighoff einstecklauf for a good member here who bought a drilling and the insert from me.
Decent claw mount installed and regulated... $1,000-1,500 for mounts; you supply a good scope, or Lee will sell you one. They might be more, now that AKAH is no longer making basic sets to fit and file in.
Recknagel swing mounts are a bit less and are a very good choice. They are the mounts on the drilling in the bottom photo of the linked page.