Me again
I was looking for something to do so I did some more research and found some information that sounds plausible to me
Assignment of mortgage from Thomas Adams of Walsall, co. Staff., bucklemaker, by the direction of John Wilkes late of Walsall, then of Darlaston, co. Staff., gent., to Thomas Blakemore of Darlaston, ironmonger, of lands and premises in Darlaston. MS 3449/Acc 1939-023/513514 22 February 1790
In some other articles it states that he was a buckle maker and he shared the premises with a Harness maker so I think that it is plausible that he made the plough gauge.
Cheers
Nick