I know it's been a long wait thinking you're all on your own as a descendant of the Sinkinsons of Kendal !
Well I am pleased to put you out of your long & lonely misery as I am also descended from the same Sinkinsons of Kendal !
It's such an unusual & apparently very Lake district-focused surname. I originally asked Genforum to list it because until last year it wasn't on the surname lists.
My 3X great grandmother was Jane Sinkinson chr. 3rd March 1819 Longsleddale Kendal. Married 22nd August 1837 at Kendal Parish Church, Edward Martindale (1815-1874) of Benson Hall, Selside,nr Kendal. Jane died 5th September 1858 at Benson Hall,Selside nr Kendal and is buried in Selside churchyard. The Martindales were a large family who farmed lands around Selside just outside Kendal.
Jane was the daughter of Robert Sinkinson & Mary Harrison who were married 9th June 1811 at Kendal.
Jane's siblings were per IGI :-
1. Mary chr.23/12/1812 Kendal 2. Mary chr. 17/10/1813 Longsleddale 3. Ann chr. 01/09/1815 Longsleddale 4. John chr. 09/02/1821 Longsleddale 5. Agnes chr. 18/07/1823 Longsleddale 6. James chr. 19/12/1825 Longsleddale 7. William chr. 19/01/1827 Longsleddale 8. Elizabeth chr. 03/06/1830 Longsleddale
I guess there has to be a connection with your Kendal Sinkinsons, most probably your Thomas being a brother or cousin of my Robert. The dates would certainly fit.
I'll see if the IGI throws up any more information. If you've got any more family dates & details in the menatime then do please let me know.
Jane and Edward Martindale had a extensive family in Selside and I am descended from their daughter Agnes (1849-1897) who married Richard Grisdale(1846-1876). I have been in touch with many Martindale connections descended through Edward & Jane via Genforum.
Hoping to hear from you soon Best wishes & regards