Edit… Just trying myself to put your engine numbers into his calculator… and 12H goes in fine but 616 is not on the list, I had a similar problem with an engine of mine, the number of which started 12H 6_ _ (something something… i cant remember, possibly 694) and i came to the conclusion it was an austin 1300 engine, still A series, but not mini. This last statement i’m not sure on though, so please don’t take it as red! I’m sure someone on here will know more definitively though.
Yeah, apologies for that, not got round to doing all the A series engines yet, however there is an FAQ which does cover the basics of the older engine codes.