Would it be possible for someone to measure the position to the rivet holding the tool roll retaining strap in the boot.
Not sure if there is some sort of reference point for measuring that I could then measure from to mount mine.
Any detailed photos of the original rivet and strap also greatly appreciated.
Regards, Graham.
It goes ahead of the fuel filling hose cover. You should have only one hole in this area. It was a self tapping aka sheet metal screw, in fact there was a Service Bulletin warning about a screw being too long and cutting the tire on hard cornering, and we concluded it was this screw.
Regardless,
Many original XK120s had the tool-roll/kit strap pop-riveted in place.
Maybe an improvement following problems with overlength screw?
Cant say I have confirmed original examples using a self-tapping screw, but I do have a few showing a pop-rivet
So probably an age related issue, albeit no idea of demarcation, but I suspect earlier rather than later.
Roger Payne
CANBERRA
Australia
rogerpayne@bigblue.net.au
FWIW my 5 / 54 build car certainly had a pop rivet.
Very good, yet another detail for us to chase down. 
Mine had a very small hole, too small for a pop rivet, had to be a screw.
Mounted tool roll today. I’ll take a photo and post it tomorrow.
Next are all the tools retained by the Terry clips. I have marked these out from a stencil I had of the original positions.
Graham.