There is limited history detail available for this camera. Dai-ichi seems to have developed in 1947 out of a company called Okada which made medium format folders. After 1956, it became Zenobia, carrying on the name but for 35mm rangefinders only. The original Zenobia was a 120 folder from 1949.
The Zenobiaflex dates from 1953 and seems to have been a solitary TLR for the company. Interestingly, Sugiyama has it shown as a "Zenobiaflex I", which sort of implies another version, but I have found nothing to indicate that this was the case.
Either way, this is quite a nicely made camera, with a solid feel and fast shutter.
Taking lens is Dai-ichi Neo-Hesper 75mm f3.5
Shutter is Dai-ichi Rapid 1 to 1/500