You'd be surprised. There are quite a few of us in that age group. There are several here who have collected as long as I've been alive.
So I opened an account this weekend on acsearch and started hunting. The Abydos coins were the only ones that looked at all similar to mine. The obverse die on Price 1551 seemed to match closely. Here are a couple of examples: So what do y'all think? Are these close enough to definitely attribute the coin to Antigonos I of Abydos? Also notice the depression at 12:00 on both these examples. Perhaps that solves the mystery of the bankers mark, failed hole or whatever else caused the depression on my coin. When I examine the depression on mine it looks worn around the edges and has black patina on the bottom, which tells me that it isn't recent.
I think the symbol in front of Zeus'knee in the opening post looks more like an "ME" monogram. Have you looked at Price 1560 ?
BTW. with the "depression at the top of the obverse" don't you mean the eyesocket and nostril of the lion ? These are part of the design and supposed to be there.
I'm referring to the depression at the center of this blown up photo which is the top of the obverse of the OP coin. Some people speculated that it is PMD (bankers mark or attempt to pierce the coin for a necklace) but the obverse die of the Price 1551 I recently posted looks to have this "hole" in the design.