I’ve got an older 80s wheel with a Regina 7 speed freewheel (I assume it’s freewheel and not a cassette) on a Dura Ace hub.

I want to remove the freewheel to service the hub, but there seems to be a cap or something covering the center area where the removal tool goes.

Does this thing just pop off? Is there a trick to getting it off? I don’t want to go prying at it and mess it up if there’s something I’m not seeing.

Thanks!