Year of Manufacture
It may be worth considering a separate title/category for those seeking the date of their engines manufacture and any allied information eg TBO.
I suggest this as ;
I doubt there can be any debate or sharing of opinion, on the request itself or its factual answer(s), usually from our learned expert(s).
It seems to me most contributors/participants are either seeking or imparting advice/opinion from which we all can learn - the date of manufacture (important to the requester) is unlikely to elicit any such debate.