Thanks for the nice comments. I have always wanted one of theses 24 hour guys, and was very happy to find this one on the GF bracelet.
It's interesting to me that the UG shares so many things with the Heuer Autavia (both are late 1960s, manual-wind chronographs, in 40 mm round cases, with rotating bezels, with classic movements, on GF bracelets).
But in other ways, they are very different watches -- starting with black and white dials; the 12 hour and 24 hour indications; the movement makers (Valjoux and Venus); small and standard size registers; numerals or markers; snap-back (compressor) and screw-back cases, etc.
Still, they share a look / style / vibe . . . classic 1960s chronographs, before it all went crazy in the 1970s.