I have stated this (and am NOT an Acer-Mex expert by any means) based on dimly remembered personal history: I convinced my brother-in-law to buy one of these when the brand first came into LBSes in SoCal and recall that his (red) did NOT have forged SunTour dropouts (just stamped steel plate) and the decals said simply "Carrera" but later offerings came with those DOs plus with "Sport" added. Still later the Carrera "line" seemed to grow to include some mor models and one had Tange tubing (tho probably something plain gage like Tange no.5) where these early frames were (IIRC) nothing with a tubing brandname and heavy enough to be lowly "gaspipe" steel.
I am not sure that the headlugs are actual Agrati (Bozzi) products but possibly Mexican-sourced copies since they certainly did not use the forkcrown, nor the Bb shell from Bozzi, and I'm doubtful about the seatlug, too. But juvela may know details here I'm unaware of.

And given my porous memory I would take ALL I write with a grain of salt.

BTW, that Windsor "Carrera" got stolen out of his garage within a year and he went on to ride different bikes (some much better, some not) in the ensuing years, we were both kind of glad that bike "went away" only cause there was some buyer's remorse after he took my un-earned advice.