The hallmarks tell me it's 1781 London and also the fact it has no tax duty stamp and is bottom-marked which vanished end of that year.
The makers mark is worn or was badly stamped but has a distinctive curl to it.
Looks like a whispy B or G. Hester Bateman was an initial thought but it doesn't seem to match up.
Only remotely similar item i've seen without a scalloped bowl but feathered edge and 'onslow' handle was 1774 by William Fearn.
Be interesting to see what it actually is for too.
![Image](https://www.925-1000.com/pics/Ximg.jpg)
![Image](https://www.925-1000.com/pics/Ximg.jpg)