That would be Leith Glass, not Leigh.
But this looks to be a lot more recent than 1820s.
Something is muttering away at me here. It is muttering Helen Munroe-Turner. I know she did work with Juniper Green, but Leith might have been involved.
The few pieces of her work in the Studio glass style that I have seen tend to use a lot of white glass and be a bit crude. Kind of very not unlike this.
It would be a long shot, but I think that could well be the name to start off with finding out a bit more.
I may be completely wrong!
I have just got out my book which used to belong to H M-T. She wrote Turner inside it.
Her writing of Turner is not incsistent with the writing on this - which is on glass, not paper, but the way it goes and gets a bit iffy between the r and the n is not dissimilar to the way it goes a bit squiffy between the u and the r.
Letters individually are similar.
I am no handwriting ex-spurt, and don't give much credence to that sort of thing anyway.
I have at least 3-4 totally different writings and styles.