Gervas' grandfather John is the mystery man as I have been unable to trace his baptism - 1732 seems to be a guess date given out by others though their is no clue of place of baptism.
Galloping through the Misterton Lindleys it appears that this is where the Epworth, Finningley and Bawtry originate from. I suspect that the Owston Ferry Lindleys originate from Misterton too - yet to be proved... I suspect that John may have been born earlier... yet to be proved...!
I didn't reply to you regarding the Slingsbys - this was some time ago - really chuffed to find that all the Isle Slingsbys connect back to Owston Ferry - so I have many distant relatives out there!