The bridge is what's called a Gibson ABR-1 Tune-O-Matic (which does use slotted adjustment screws), Gibson used to use them before they switched over to the Nashville Bridge (which uses the phillips head style screws).
The guitar I traded for the SG was a 2010 Fender Mexican Standard Stratocaster I bought from Top End Sounds for Au $999.00.
Some Genuine Gibson USA SG Standard guitars actually did have scratchplates shaped same like the one on my SG:
https://www.google.com.au/search?q=G...k9yfRFddoaA%3D