That's some kind of weird non Weber grates, but it looks like you might get a good sear out of them. The slats are facing the proper direction. I can probably come up with the flip up parts you need for adding the swing up shelf if you want them.
Sadly, to convert it to propane, you need a manifold, which is probably not available anymore, so you'll be trying to find a donor grill. You could also swap out the house for a regulator, but it'll run pretty hot (natural gas has less energy than propane, so the orifices are bigger).