Thanks Rich. Shame about the gauge, I know he was hoping that could be left intact.
At least I know it's possible so I'll drop John a note at Hydrographics to see if it can be done with gauge and estimate of cost (unless anyone else can advise on a possible source?).
RAW TM1000 [.177] || S&B PMII 12-50x56 (That's right... just one rifle!)