Ha! I set myself up for that one, and I realized that after I typed it!
So moving onto the back end with fresh measurements from my visit. I was only about a half inch off on my initial tail panel layout with regards to taillight placement. I'd say that's pretty good seeing how all my measurements are based off a 1/18th scale model and a ruler. The thing is, these were all built by hand so no two are identical, but the placement of the tail lights is based off a buck so that distance is relatively similar among all the cars. Still, I wanted to make sure things up. The lights are tilted a little and follow a body relief line and also follow the contour of the panel. So lots of measurements before I start hammering panels.
After an exhaustive 2yr casual search, I finally found the wheels I've been looking for! The factory wheels are 16x4.5 and the tires are 16x6.0. I found the correct Michelin X R185 tires, but the wheels always escaped me. There were there styles of wheels that I've seen on 507s other than the show car which had full caps but never offered: 10 hole steel, 4 slot steel, and Rudge knock off. I wanted the 10 hole style and these are just about as identical as I could get. They're Jeep wheels (M151 Mutt), 16x4.5, and 10 hole with a convex style center section. Woohoo!
I'll modify the holes a tad too mimic the gumdrop shape of the 507s a little better, but (enter Survivor's song) the search is over! Man, Google must think I'm nuts with my searches..."10 hole Steelie....Steel wheel 16".... Factory 16x4.5 steel... Big Boobed Brunette... Oh, wait, how did that get in there?!
Anywho....BMW butt to follow!
Cheers
Dave