McLeans from Abbey parrish (18th century)

[USCRx]

My McLean ancestors are from the Abbey parrish. Alexander McLean married Ann Lang, both of the Abbey parish, in 1763. [16/07/1763 MCCLEAN, ALEXANDER (Old Parish Registers Marriages 559/ 40 195 Abbey) Page 195 of 712]. They had at least 4 children in Scotland (baptized in Paisley in 1766, 1768, 1770 & 1773), before emigrating to North America in 1774, following their pastor in Paisley, John Witherspoon.
Family tradition has it that they originally settled in the Paisley area from the island of Mull.
I have quite a bit of information about the family once they reached North America.

I've been unable to find out anything about either of this couple (McLean & Lang) in Scotland other than their marriage: birth(dates), parents, siblings, etc. I've researched ScotlandsPeople, FamilySearch, Ancestry.com, etc. I'm planning a trip to Scotland next May, 2019, and would like to do as much research before I go. Any suggestions of next steps in my research?

[USCRx]

One other research clue - Alexander McLean was a silk weaver in Paisley before emigrating in 1774. He and his family were said to have sailed to America on the ship, "Commerce," in 1774.

[LizL]

I live in Paisley and on my visits to the Heritage Centre , I was advised they had a list of Paisley Weavers but I’m not sure what years would be covered. Unfortunately, the Heritage Centre , previously within the Central Library has been moved while the Library is refurbished. I believe the resources are now being held at the Thread Mill Museum but I’ve not been over to check. It might be something to keep in mind for your visit

[goldie61]

There was an article in the Who Do You Think You Are magazine in Sept 2012 about Paisley weavers.
It's about the Shawl weavers, which of course Paisley was famed for. You ancestor may well have been one if he was a weaver there.
Not that it mentions your specific family, but interesting for background.
It has this to say about records at the Heritage Centre.

Drop me a pm if you'd like the rest of the article.

[DFG]

One other research clue - Alexander McLean was a silk weaver in Paisley before emigrating in 1774. He and his family were said to have sailed to America on the ship, "Commerce," in 1774.

I also had an ancestor on a ship "Commerce" in Feb 1774, landing in New York (But I don't know where in New York) - do you have any information on the ship?  I have been trying  to find picture(s) of the ship and information on what happened to her.  Also of interest to me, Colin Gibson was on that ship with his wife Janet, but I can not find ANY information about Janet after that 1774 manifest. 

It seems that cousins and maybe a Gibson Sister came over with Colin.  Looking for as much information I can find out about the ship, Janet, Colin and their life in Scotland before getting on the  Ship.  When we were in Paisley there seemed to be a lot of Gibson's, but DNA test didn't help find any relatives in Scotland.  I have to believe that there are some there. 

Any help appreciated.