28 Drum tailight location

[Tinbasher]

I'm trying to get my tailight back in the right location. I thought that my 28 Sports coupe was later product then it is and I welded up the holes for the tailight brkt. on the left side. I did a good job and now I can't find the marks for the three holes. Can anyone get me a measurement from the end of the crossmember (Rear Body Rail) to the first top mounting hole. With that I should be able to drill through the weld and find the hole. From there I can mark and find the other two.

The Old Tinbasher