You've just reminded me that I still have Dino's Sparco side mounts welded to some OEM sliders. I had to check if they fit and either pay up or hand em back. I don't need em
@Dino, do you want to sell them on via me posting out? Or no doubt you'll need them again one day for another lude!
Merlin: Bolting would quick and easy like you say, those studs look good enough on one side but you may have to remove all that hinged part with an angle grinder and then bolt that one in. If it helps, my bride sliders look about the same depth as the OEM's and you can easily get some bolts in either end without it interfering with the sliding operation. Like you say just get stuck into the passenger seat and see. Let us all know how you get on as the lack of seat mounts for our cars is a joke.