agreed it's a very nice frame and nearly certain that it's Japanese and no Moser. I think the investment-case seat lug indicates the seat-tube socket angle (73.5°) and there's that mysterious "double-S" stamp on the bottom of the headlug that I had *thought* was an Eisho branding, but have been corrected and we still have no idea who makes these lugs, but they are nearly always on Asian frames. Seems like the fork is either a replacement or possible just sourced from another supplier (Tange or Ishiwata) by the frame builder so could be OEM. But note the carefully detailed stay ends at the dropout where these fork blade ends are just domed. All in all this may turn out to be as nice a bike as a "typical" Moser (subjective, I know) but I'd strip off those decals.