Originally Posted by s0upb0ne
looks like a knockoff of a IWC Portuguese.
It is actually a copy/reissue of the chronometer used by the Chinese Air Force in the early 1960's. The story goes that the Soviets were offerred the tooling for the Venus 175 around the mid 1950's but they already were happy with what they previously got from Valjoux (with later improvements it became the ubiquitous and sturdy Poljot 3133 movement). As relations between the PRC and the USSR were cold to say the least, it was not politically feasible to get military chronometers from the Soviets. So when the Chinese were offerred the tooling for the Venus 175 they took it - with development it became this movement (ST19 is apparently a civilian designation). The model is called 1963 unofficially because it mirrors the chrono of that period. Frankly, even if it were a copy of an IWC, it is not such a problem for me. THis watch has its own character and quite the provenance and history
Edit: gdl203: Excellent point regarding the servicing. Especially in these days of Geek Squad-style watch repairs