Looks to be 22.5" (maybe close to 23") TT to me? I haven't built it up to see what it sizes up like, (maybe I should!), but the previous owner was around 5'10" I think and ran a fairly long stem, so I'm guessing this'll suit someone around 5'6"-5'10" or thereabouts (at a really rough guess!)
On closer inspection, I'm not sure of the condition of the headset (will still include it, removed from frame), so will now drop the price to £400 (PLUS POSTAGE)... c'mon guys, this is a good deal on a beautiful and unique frame!!