Hard to say Paul, but these didn't look too weathered. Plus, with where they are situated and all, I'd say more likely something someone dropped while walking the dog or jogging along the sidewalk.

Sorry, I didn't look super hard at it, but my impression is that it was a longer lanyard made of webbing that had a complex sort of pattern to it. And it appeared to be the sort of newer car key that has the lock button on it. Didn't catch the make. Kicking myself. Hope that helps.