Michael Poulsen Gibson SG GT

yup... had to look him up, but yup

They're a decent band, slightly reminiscent of eighties metal that wasn't screaming, or full of spandex, a little bit like the untouchable Iron Maiden, only a bit heavier, with a little bit more of a modern touch, and I think they add Americana into some of their songs, I've definitely seen the bass player use an upright at a gig, on youtube, a few times.

You do all know it's not a signature right (It might seem obvious). It's just an sg gt, a discontinued model, in black, and white. Apparently it's a shocking guitar according to a website called chorder, which doesn't sound very reliable, as I've never come across it before, in two years of internet guitar trawling.

yeah, I've seen that oddball GT in person (usually in blue and white, but maybe twice in black and white). Its been awhile since it was on shelves all the time, but like I told the OP they are around! As to the neck shape? Tough to say. Every Gibson is different. Once you locate a black and white one there is no guarantee it will have a 50s roundback profile!

There's been some talk about Gibson here, so this link wlll explain to you how Gibson built their overblown rep:

https://reverb.com/blog/gallery-1950s-letters-with-gibson-concerning-one-doctors-electric-guitar-purchase?_aid=listingrelatedarticle

a quality product for almost every type of player in the "golden age of guitar building" and massively attentive customer service from even the busiest higher-up....you hafta read this shit! Gibson realy worked ahrd tog et where they got in the electric guitar age, though they have done little since the 60s to maintain it. But I just don't see Fender corresponding like this with an amature-level, mail order customer as late as 57. Its a shame but I think Fender's Henry Ford style had a profoundly negative influence on Gibson as they tried to hang onto their market share. When these letters were written Gibson was an enormous manufacturer who still marketed a hand-made product built to spec by skilled craftsman, continually innovated but even under Ted "corporate America" McCarty they made time to treat every prospective customer with the individual attention the purchaser of this sort of instrument deserve. Ah the glory days.

From what I can see Gibson Memphis ahs been attempting to revive the old Kalamazoo spirits. Its a shame the buy in is so high compared to the average modern income, but that's also a product of runaway inflation and a dearth of quality, sustainable sources of their traditional tonewoods. In Memphis they seem to communicate heavily with their customers and continually strive to offer innvations and reproductions to meet the demands of their fans.