Doing some more digging I found the following (this is a translation from the Czech language):-
The prototype of a two-place aircraft by designer Ing. Tomas flew for the first time in April 1956. Let launched flight tests. Given the continuing difficulties in the development and taking into account the number flying the C-11 project was cancelled.
I believe that only two aircraft were built V-01 and OK-08.
Together with the "What Cockpit" thread this thread provides a wonderful platform to learn about unknown aircraft and aircraft development.
Mel