As I wrote, I ordered both the Marina and the Mikromask and wanted to compare them side by side to see what the differences are exactly. Unfortunately, I received only the Mikromask - Marina was no more on stock although it was marked as available in the online store. I can post detailed photos of my Mikromask though, so that those who own Marina can compare them.
As for the buckle - I do not know if it is identical, but if I broke it and needed a quick and easy temporary fix, I'd simply put a wire through the holes on the fixed part of the buckle (the frame) and fixed the rubber band on it - having the other one adjustable would be sufficient. At least for couple of days it should be pretty sufficient solution. You will be probably able to get a spare buckle from a Technisub in the meantime.
As for the buckle - I do not know if it is identical, but if I broke it and needed a quick and easy temporary fix, I'd simply put a wire through the holes on the fixed part of the buckle (the frame) and fixed the rubber band on it - having the other one adjustable would be sufficient. At least for couple of days it should be pretty sufficient solution. You will be probably able to get a spare buckle from a Technisub in the meantime.