I believe these yellow/rose gold chronographs are very typical from the 50s era, UG produced many of them showing some slight differences with the case, hands, ...
Here's a period ad showing one of these "standard" Uni-Compax
The first known UG case reference showing this typical bezel is the 124116 introduced in the early 50s
as often with UG, these have been offered with several dials (and hands) types
Later on, UG introduced the 124146 reference, a 38 mm diameter case
Here are the key details of these
They're powered by the 285 Cal.
The bezel is slightly wider than the the previous execution, the H/M hands have also a different shape, the red telemeter scale is fairly unusual in the UG production
the lugs show a subtle curve
blueish hands are a typical UG trademark
As many UG chronographs references, these have also been offered by Zenith with a specific dial and reference (this one is 124146-4)
All of these details offer a classy 50s flavors chronograph with its own personality
A real joy to own and wear I love to nickname my "UG Thunderbird"
Shipkeeper, congratulations for your Medico Compax, it is outstanding and hard to cross, thank you for posting this one.
Best,
Laurent