Mick - I agree about the lack of evidence (either way). I was merely pointing out that the OED's 1882 source was a local glossary, but they had plainly not used the earlier source of Nodal and Milner. And if the OED can't get it right then there's no hope for any of us!

Nodal and Milner say, in the introduction, that their work seeks to include:

"All dialectal words known to have currency in the county, and all archaisms the use of which at any period can be verified, have been comprehended in the Glossary, without reference to the fact that some of them may be in use in other parts of England."

The fact that 'Jerry' is not given a specific date may imply that it had been in use for some time previously. I think we can both agree that that might be difficult to prove.

I'd be interested to know how Bert came up with 1804!