And here he is, lewisjnoble himself!! Currently on Unst in Shetland, main focus of this trip is walking rather than cycling.
My Sherpa is v similar in spec to the lightweight Sherpa in Thorn mega brochure menus, C2 I think. XT cranks and brakes (minimal weight saving there), Tubus Vega rack (useful saving) 853 forks (same), but the biggest factor is the DTSwiss rims, 1.6 Supreme tyres, light tubes. The wheelsts made a massive difference and transformed the bike. Very lively, still fine for moderate loads, but no front rack on those forks. My newer Thorn Audax is lighter, and a livelier, but the Sherpa is brilliant in fast moving / changing urban traffic and on rural roads.
Good luck. May not be able to contribute much more, very intermittent signal at campsites.
Lewis