...and it looks like the sort of thing that would be used as a toothbrush holder, or a vase that's contained inside another pot. The last possibility is, I presume, what it has been used for as it has blushing and deposits inside. The lip on it would make it awkward to drink from, so I'm sure its not a tumbler (as was stated).
The "vase"? is not very large 3 1/2" tall, 3/8" wide lip, 3 1/4" diameter at the top and 1 5/8" across the base.
Aesthetically it has nothing going for it at all. I'm just curious (as always) as I've not come across, what is essentially, a liner with a Sowerby mark before and I could find nothing through the boards search feature. Nor, anything in the pattern books that look a a multi-part object with this shaped piece. So, does anybody have any ideas? (other than chucking it

)