Trying to find any information on this small piece of pottery

It is 5.5cm tall and 8 cm wide

At a guess it could be delftware, either from Holland or English. Just the amount of chips on the rim. But the blue colour isn't that strong so it's kind of putting me off.

If you search for 'English delftware ointment pot 18th century' on google images you should find one similar. Can't say that that is a 100% correct attribution though as i'm not an expert. It might be a good idea to show it to a museum.

I'm pretty sure that it's an open salt cellar, probably 1860 - 1880. The transfer blue decoration will have been adapted from a pattern such as Asiatic Pheasant - where there wasn't room on a piece to apply the full pattern they'd typically use a piece of border transfer so that it would still match the rest of the dinner service.
I've seen the impressed circle mark on a number of Staffordshire Willow pattern plates from that time period over the years.

Thank you all so much, your knowledge is so helpful to me.