I measured from the ST to the TT with a protractor.

To double check the protractor, which is not super easy to read, I did some tape-measurements and some trig to compute a STA. These are all c-c, rounded to nearest cm:

ST = 56cm
TT = 57cm
DT = 61cm
HT = 9cm

The HTA is around 74 degrees. Based on that, the math projects a STA slightly below 72 degrees. Close enough to the protractor.

This frame has no other "touring" features -- no canti brakes, minimal bosses (sadly) and shorter chain stays; the 28mm rear tire is within 1cm of the seat tube. So it's a roadie, it's just got that low, lax STA. It's an oddball.