Well thanks to you all for the info, will be a great help and yes, I think that screw is the problem.
If I gently pry the sear down with a screwdriver the slight movement allowed the safety to slip by and engage the safety and keeps it from firing when trigger pulled, thought I would have to file something, but nope, think the screw is the issue and I will try screw it up a bit to take some pressure off.
Will probably have to wait till tomorrow but will try it.
Big thank you to all again, great resource here.
Just purchased another rifle at auction: non-Restricted - Ruger M77 in 270 Win - This bolt action rifle with floor plate magazine appears to be in good to very good working order. Barrel is 22", rifling is good to very good, bluing is good as it is starting to turn grey, has no sights but has integral bases, stock is good to very good, rubber butt pad good. Ser # 74-00533 about 1979 in 270