The most obvious difference (though subtle) in this photo is with the belt lifter. The 508 belt lifter used the same script as that found on the 505. But notice the difference in the 509 on the right. That belt lifter was used all the way through the Model 515. The other difference that's not obvious is with the headlight trim. The 508 was still using three pieces of trim. Each piece was held on separately by rivets. On my Model 508, a previous owner had new rivets installed in order to use the one piece trim that was introduced on the 509 (on right). The 508 on left has a sprayed out bumper. The 509 on right has the original bumper. I was able to match the trim color pretty closely!
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