Seen the exact same stuff on AliExpress for about 5 EUR incl shipping, but there they claimed it's 7 speed max. Apparently they aren't? I think I'll give these a go, thanks again! It's gonna be for a budget build anyways, so they won't look out of place.
It might be a little funky with some of the modern cable pull ratios.. But I run a Sram X7.2 on 3x9 setup with 6-speed downtube shifters mounted on thumbies and it works even if it shouldn't.
So my guess is you're good to go.
On the other end of the spectrum you get these, which should do the trick - but they won't get you any instagram likes.