I have owned my 1960 MK1 Morris mini minor for 3 years now and have finally today started to look at it, It was a genuine barn find 3 years ago having been with the same person for 30 years prior and have been parked in his barn after his wife drove it for the first time and hated it, lol. There was something obviously wrong with her

I have decided to put it back to completely original and today tried to fire her up, obviously having been sat for 33 years things are some what seized but after removing a few bits I got her to turn over. So all is not lost.
The reason for my post today is that I thought I had found the HOLY GRAIL when I looked at the V5 and is says 970cc, alas it is not of course but I dreamt for a minute.
Now my engine number on the Heritage cert is 8AM-U-H/74689 which with this being a sept 60 car feels to late, the actual number on the V5 & engine number on the block is 53495, random and then on looking at her properly for the first time today It seems I have a Gold seal Either engine or Gearbox.......... Now there are various numbers on the Gear box 22A363 which is definitely correct and another number to the left (as you face the engine) stamped on which say &6916, any ideas at all??
I have had a look at all the gold & Silver engine numbers that I can find and NONE of them match or even come close. Just for reference the Head stamp is correct for a 848cc which is 2A629.
I'd appreciate any help or advice on this as keen to find out what it is I exactly have.
See pictures https://imgur.com/gallery/icEyFgD
Kind regards
Samuel