Mine is very similar to yours; although there are a few minor differences. On the right side of slide on mine it states "WARNING: RETRACT SLIDE TO SEE IF LOADED. FIRES WITHOUT MAGAZINE". On the frame below that on the right side it states: "READ MANUAL BEFORE USE". Mine is stamped STAINLESS on the top of the barrel and in the front of the slide.
I purchased mine new on Jan. 29, 2010. It also has the stainless controls like yours. I suspect yours maybe a little older than mine due to the lack of the above stamped wording. Mine is not marked anywhere, I am aware of, the wording INOX. The factory box does state on the label: MODELO - MODEL 92FSINO. The CODE block is: A564S611100100, and the CATALOGUE CODE is: JS92F505. The ORDER is: U00. The serial number is M53746Z. I am sure something in the above indicated the date of manufacture, but I do not know the answer therefore do not know the date of manufacture.
I did not remove the grips to look underneath on the frame since I replaced the factory grips with Crimson Trace grips and have it zero'ed in. I put the original grips back in the factory box for safe keeping.