Seems like our line of McLaren may originate from Peter.
I have a middle name of Watson for him. Does that name have any meaning for you ?
I feel more info on Peter is needed to complete the connection. I only know that he was deceased by 1844 as indicated on his son John's marriage certificate.
I believe I have a photo of John which I'll find and send through, perhaps this may show a resemblance to any McLaren photo's you may have.