Actually, the A-75 came out the same time, more or less, as the A100. The 100 is an evolved A80 and as such, is an older design. The 75 came out only two or three years before Astra went under. The 75 uses the Sig style lockup (rather than the Browning style of the A100) and has a single-side trigger bar (which helps it be so very smooth) on the right side. It is also a single-stack compact whereas the 100 is a double-stack full-size combat arm. Having owned both, they are very different but do have a similar aesthetic. In any case, Astra was a fine pistol maker and its collapse is a real shame.
Ash