Fitting seatbelts - 58 bug

Hi Guys, I'm welding seatbelt plates (with nut welded on back) to my 58' baja. I've got the front locations sorted but I'm not sure where the rear holes are supposed to be. Could someone post a picture or sketch? Many thanks.............Greg.

What sort of seatbelt? 4 point, inertia reel?

For my inertia's the top plate went in the corner just below and in front of the side window.

I'm fitting 2 lap/sash belts in the back. I've found location near back window and each side of centre tunnel floor from photo but I'm not sure where the outer point is suppose to be.

Ok here is the link to the page of my build thread for a 59 Beetle with inertia 3 point sash belts.
Seatbelt mounting points

These have been approved by an engineer for the 2 body points. On the floorpan spine I found the previous owner had popped a 63 pan under the 59 body so I already had the spine bolt hole in place. Is that the one you're wondering about?

Also, make sure you are using 7/16th UNF bolts and nuts. These are ISO regulation standard for seatbelt mounting and will come with your new seat belts