Ooh! Speculation!
Let's see...it is a Mk2 Sherpa, so the virtual top tube measurement of 550
should place it as a size 560s, same as my own late Sherpa. The top tube length "looks right" for that size (is proportional) and the seat tube height is reasonably close when measurement error is allowed-for. The serial number would confirm the size (first few designators, i.e. "560S").
If I were contemplating it, I'd change the front mudguard stay-attachment points to the Thorn mid-fork bosses and I'd level both racks.
I *think* this may have been a frame buildup...the front rack is a Tubus and so is the rear, neither of the mudguards are attached in the Thorn manner, the stem is not Thorn-issued and neither are the handlebars and if those are Deore v-brakes, the mounting bolts aren't the originals (stainless replacements just as noted in the ad), and that's not likely a Thorn-issue outer Deore chainring (note the guard) -- or it may simply have been personalized and have had a few parts replaced (the mudguards are new judging by the even gloss, but lack the little front rubber "flip" at the bottom and cap at the top. The kickstand in the rear triangle shows evidence of fitting with care. The saddle looks more weathered than the rest of the bike, but may have been installed for the sale. The rims have sidewall wear indicators intact, indicating long service life left, and I'm guessing they might be Exals. A lot of thought has gone into this one...there's even a chain watcher on the lower seat tube to prevent chain derailment onto the BB shell (I run NGear JumpStops on each of my der mech bikes; this might be too). The steerer appears uncut, thankfully.
It really does show very well and looks as-new in the photos. The price seems a bit high compared to the basic 560S drop-'bar build shown in the 2011 brochure (
http://web.archive.org/web/20111005125116/http://www.sjscycles.com/thornpdf/ThornSherpaBroHiRes.pdf ), but it includes the XT hubs, both racks, rear panniers, 3 bidon cages, the chain watcher, pedals, bell, sus seatpost, computer, and the kickstand. I'd almost bet money the owner has put shellac on cotton handlebar tape. A lot of care and thought went into this.
Best,
Dan.
