The beret is in good but worn condition with the liner removed and the fuzz worn down, this was done on purpose by Special Forces members, something still done today.
The beret appears to be an early model from the 1960s and is potentially Canadian made.
The beret flash is for the 10th Special Forces Group and has a set of captain's bars affix to it.
The 10th Special Forces Group served both in Europe as well as the Middle East and the Congo during the 1960s.
While the 10th didn't serve officially in Vietnam many of their members rotated in and out of other groups fighting in-country.
If you have any questions please let me know!