Hmm, what an extraordinary name Peregrine Knowles was!
Now I know that the familysearch data is incomplete, but entering his name, all years, England, only brings up his birth/christening and marriage records!! A familysearchwhack of sorts....

So he probably wasn't hiding when he added Docker(a)y to his name.
I wondered whether any of his siblings had also adopted the Docker(a)y name. However, the only other Knowles born in St Marks, Lincoln was Jane b 1733

No Dockerys christened in the parish.
Peregrine's parents were William & Mary. There were no Williams born 1750-1790 to a W&M couple in Lincolnshire; the only Mary to a W&M couple 1750-1790 was ch 18 Jan 1787 in Fiskerton, Lincolnshire (this Batch C028272 also has to a W&M - Hannah 1788, Elizabeth 1789, George 1794, William 1797; no Docker(a)ys christened in the parish).
I cannot see a will for Peregrine on TNA site.
Docker(a)ys and variants 1740-1820 seem to be associated with Cambridgeshire, Cumberland, Lancs, Herts, Yorks.
Keith, do you know Peregrine's occupation? Or that of his children?
As there is an east coast bias for the Dockery name, could Peregrine have had an association with continental Decroy/Decrois businesses? Lace making, cloth manufacture, for example?
Kind regards
Gaie