Yep you remembered correct about that 4516-2.
I also bought a bunch of those extended Ed Brown offerings “back then” and had them on a few of mine, (45, 9mm single and double stack.) Only the 645 has them on now though cause it only goes to the range and I really like that “vintage” look.
I suppose I should find a new home for the other’s cause I will NEVER put them back on ANYTHING I have again.
Jim