there doesnt seem to be a picture attached. Perhaps you could send it to my regular email at firstname.lastname@example.org
I am convinced this is the same family. The name Watson fits, and the name John Alexander fits because Peter had a brother named John and his father was Alexander. Did Peter have siblings? I have lots of McLaren information I can send you if you are interested.
Which country did John Alexander end up in? I gather you are not in Scotland?