I have WK sliders, I can't say for sure but I'll order a set of your gussets before the weeks out and find out one way or another (not concerned if I have to modify something)
It's probably just me but I'd ask him about anything else he may have touched while owning the thing because anyone capable of doing any/all of that without noticing whether in a hurry or not I'd worry they were capable of turning the ignition key the correct way to start the truck let alone...