Is there anything missing from inside this cap?

If so, I wonder how long it's been like this

The center ball/carbon

That's what I thought. Never seen one without the carbon, it's been so long since I had the cap off didn't know if MSD slipped one by me.

Wonder what the heck happened to it

Probably fell out when you were cutting the cap for clearance....???? lol

has it been workin like that?

Well after sleeping on it, yes I remember exactly what the carbon center is like in the MSD cap, it basically just "plugs in".

Chapper, this cap was relieved a looong time ago and yes it was in place but can't say exactly how long it's been missing.

Bonefish, I drove it around the neighborhood and in the garage at the least like this
That's the last time the cap was off and I didn't find it on the trailer floor either

More than likely its laying in the bottom of the dist body..
if it was even slightly loose it could vibrate around and wear
the sides and fall out as soon as you lifted the cap

Bought a new cap last night. The center electrode fits tight so doubt it would just fall out. No sign of the old one anywhere

Oil system is primed, ready to run so I'll grab some fuel this afternoon..... then make some noise this evening

happened to mine after about 8k street miles, i replaced it with a black summit brand cap.