Not wanting to upset Andy, but having seen this in the 'steel' it's certainly not unused, and defo not 'mint' by my book.
Certain components are defo immaculate, as they were brand new boxed bits fitted to replace used ones - but the frame and forks are clearly used.
Not that this detracts from the whole, but just wanted to bring a little clarity on this for interested parties.
Andy I'm sure will confirm this is pretty much a one off frameset though - and maybe share his first hand knowledge of how it came to be / how it came to be in current owners hands / and how future Zinns developed from this...?