I bought a pair in late 2011 from (then) Dennis McCann's. I think I still might have my beat up originals...not sure why though. Here's link on the new web site... SUN VISOR END RUBBER MOLDING, DINO 246GT, 246 GT Part Number 20128401
Round just like the repros I got from McCanns...but alas, it looks like I tossed them (just looked in my box of replaced-yet-hold-onto-this-stuff box.
Ah, I was able to put the item in my cart w/o any not-in-stock kind of message, so I assumed that meant they were in stock.
These look close and you can't beat the price! 100pcs Black Rubber End Tips for Headband Hairband 15x6mm 5 8"X2 8" | eBay
I picked up a pair from T Rutland ebay recently which I hadn't used; went to look and cant locate at this moment but I think they were square ended...so maybe not correct? Paul.