Maybe I am wrong but I just replaced a windshield at work last week with a similar locking strip.

Looks like the locking strip used in automotive windshield or glass weatherstripping on older vehicles. It comes in different profiles and appearance for different applications. I can not get a good view from the pics to narrow down a more specific vehicle.

References:

http://www.automobiletrim.com/windscreen-chrome.html

Reason:
Sorry for the delay. I have added more pictures that may help. It is a rubber-type material, 3/8" diameter. Large spool. Probably some type of trim, but to what, I wonder.

Maybe I am wrong but I just replaced a windshield at work last week with a similar locking strip.

References:

https://www.vintagecarparts.co.uk/products/fil-blk-windscreen-filler-strip-bl...

https://www.vintagecarparts.co.uk/m/products/1/3/2931/0FIL.DIM.jpg