Normally, the bows have different colors near the ends to help identify which one goes where but, in my case the 75 year old bows were covered in chipped paint and surface rust. Two had colors on them, the rest didn't. So, I took to the wire wheel to prep them for paint when I noticed.......... they're numbered sequentially! 7 bows in total. They're stamped C-18 up to C-23 with the last one (rearmost) having no stamp but it's clearly distinguishable in size and shape from the others. Test fitting them in the car, following the #'s with C-18 in the front and C-23 next to last, they fit perfectly! Hope this helps someone.
First I've ever heard of them being stamped, but it makes sense. Thanks for sharing, evintho. What year is yours? (I'm thinking '57 because we're both on so many of the same threads) Back when I did mine, after cleaning, I wrapped each of the bows in color-coded plastic electrical tape to match the factory color coding. I did it mainly to keep the once-rusty bows from staining the new fabric headliner, but, being slicker, also helped slip the bows in at ***embly time.