Petrus Welsch was born 3 Sept 1772 in Red Hook, Dutchess Co, NY as the son of Corneles Welsch and Lea Westphal, and witnessed by Petrus Westphal and Catharina Westphal, and then baptized on 13 Sept 1772 in Red Hook, Dutchess Co, NY as the son of Corneles Welsch and Lea Westphal, as witnessed by Wilhelmus Vooland and wife Elisabeth Velten.
Listed as Peter Wells in the 1799 Tax Rolls, on the same page as his father, with $20 personal estate and $2 tax.

In 1830 there is a listing in Cobleskill, Schoharie Co, NY two lines above his son Cornelius which appears to be Peter Wells -
males: 1=15-20, 1=20-30, 1=50-60; female: 1=15-20, 1=50-60

In the "Story of Dundas" (Ontario, Canada) by J. Smyth Carter, pg 445, he says, "The WELLS families are of American-Dutch descent. The original settler of this name in Dundas located in the Nudell Bush vicinity. His sons were: John, Henry, George and Cornelius". Unfortunately, he failed to name who this original settler was.
However, the (2nd) marriage record for his son Henry in "County Marriage Registers of Ontario 1858-69”, Vol. 18 says "Henry Wells, 62, son of Peter and Diana married June 4, 1866, Isabella Haines 55, Mariatown."