For the first time I currently have two SGs with batwing pickguards, and noticed they're quite different in shape by the lower horn. Not a big deal, but I was curious about it, especially how that might impact fitting a replacement pickguard! So I did a quick comparison by grabbing a couple of pics on my phone and overlaying them. I was surprised how much difference there was. To understand the picture, there's a 2016 SG Standard HP as a negative, just so it's clearer to see the differences - the edge of the pickguard is black, and the edge of the fretboard is blue (yellow-ish binding in negative). The positive image is a 2018 SG Custom, with the pickguard edge being white. I've done a quick & dirty alignment, but you'll see a blue fretboard edge on both sides from the HP, because it has a slightly wider neck. Frets, inlays, strings and bridge align well (inlays are different shapes), as do the bodies - apart from the lower edge and horn, which is actually slightly different. But the pickguards are really quite different: The HP pickguard goes further down towards the bridge, and runs closer to the lower body edge, but then doesn't reach so far into the horn - the only difference I'd noticed. If I wanted to swap over pickguards, there's only one screw hole that really aligns at all, and either way there'd be at least one screw hole visible from the other pickguard. Yes, I know it's trivia, but I didn't realise there was so much variation, especially on modern SGs (2016 &2018).