Surely this is post-mint-damage.

This token I have seems to have had it's hole filled with lead.  Can I safely remove this?  Should I just leave it alone?

I agree.  All of the ones listed on eBay are open in the middle.  So yours is either one of the only remaining intact versions, or someone filled it.  Maybe in an attempt to scam the machine it was meant for?
I don't know.  I think I'd almost just leave it.  It's not a particularly rare or valuable token.  And the modification adds a bit of history to it in my opinion.

Maybe it is supposed to be filled like this one.                                                                                                                                                                                                                 

glorkar

I agree.  All of the ones listed on eBay are open in the middle.  So yours is either one of the only remaining intact versions, or someone filled it.  Maybe in an attempt to scam the machine it was meant for?
I don't know.  I think I'd almost just leave it.  It's not a particularly rare or valuable token.  And the modification adds a bit of history to it in my opinion.

Yeah I was thinking about the history part too.  It's interesting at least.

Beekeeper

Maybe it is supposed to be filled like this one.                                                                                                                                                                                                                 

I don't think it is, that's a transit token that's Bi-metallic.  The token I have definitely has lead, it's very soft and I've never see a similar token with the hole filled.