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