Link to OP's picture gallery: https://www.bikeforums.net/g/user/511098

While it exhibits nice workmanship, the features suggest a mid-range frame. First, it uses Gipiemme dropouts, instead of Campagnolo. Second, it does not appear to use a Columbus steerer tube, suggesting either a lower tier Columbus set or a tubeset from another manufacturer. Furthermore there are no reinforcing tangs on the blades or bridges. I'm also surprised to see a flat top seat lug. Finally, there appears to be a fairly long serial number under the heavy paint, suggesting a mid-sized or large, mass volume manufacturer.

What size seat post does it take? Are the tubes mitred? An overall picture and one of the rear dropout would be appreciated. With that collection, I'm surprised you can't provide a definitive answer on the threading standard.