While some Boss guns have similar locks on them:
https://www.gunsinternational.com/guns-f...un_id=101161865Others don't:
https://www.gunsinternational.com/guns-f...un_id=101165081Tony Barclay would know better, but I doubt Boss's locks were ever made by Scott (the Scott Premiers I've seen inside of had Stanton-marked locks, btw).
As for that Stephen Grant, I'm almost certain John Robertson and his shop of outworkers made those guns.
There are a lot of similarities between those Grants and the Boss shotguns produced right after Robertson took over the company.
OWD