I found this antique mug with these marks on the base.
The first two are barely legible, but I believe they identify the city of Sheffield and the lion passant.
It’s the last two hallmarks that I can’t understand. Which of the two letters identifies the year of production? And could one of the two letters be the silversmith’s mark?
The Maker of these pieces was very prolific. I also have a piece with exactly the same marks. It looks like the maker of these pieces cobbled together a punch from a number of different bits, then welded them together because the mark comes though on my dish as a single punch and the spacing is is exactly the same on all the examples. When I found my piece it was an “oh wow” moment…when I got it home it was an “oh no”. Luckily it was $7. I haven’t bothered to have mine tested, assuming that it is just silver adjacent, but it polishes up well and looks nice with Christmas chocolates.