Featured Help with Silver Hallmarks (w/CLOVERLEAF) on Antique Cup

OK, here's my latest mystery... The owner thinks this is very old Irish silver due to the "shamrock" mark - but I know that is NOT the mark for Irish silver; that would be a Celtic harp. Nor does it have any regent's head, so this can't be any kind of British silver.
It is a cup - bowl shape, no handle, so may it indeed be old - but I can't find anything on the hallmarks. Rather than describe them, I'll upload large pictures, so you can see...
The cup measures 3" in diameter x 1-3/4" tall; weighs 95 grams. It shows remnants of gold wash.
Any clues as to age or origin are welcome! Thanx in advance!!

 

The silver people will get here. Meanwhile, you might try using 'trefoil' as a search term.

 

Silverplate. That's what I think, anyhow. We'd call that a clover leaf too, but trefoil is a good word. I can't recall off hand which makers used cloverleaf marks. I think James Dixon and Barker Bros did.

 

Hello! I have a locket with a trefoil/cloverleaf as well and always wondered about origin. I will see about a photo soon, but any more help from the 'silver people' would be greatly appreciated.
Thanks!
A

 

Greetings, Ameerayna! We look forward to your pics!