RNVR cap badge

[Lacelady]

Gentlemen, I've joined this forum specifically to see if any of you can shed a little light on a mystery for me.
My Dad was in the RNVR (WW2) - I can see why Mum fell for him. His cap badge is reasonably clear in this pic, and the crown is undoubtedly rounded at the top.

Recently I opened a box of Dad's that I hadn't looked in since he died a few years ago, and came across this badge. The crown is a different shape at the top, (not clear on the pic is that it's framed with little dark circles - possibly tarnished silver?)

My question is - did the RNVR cap badges change shape at some point, and this is the newer version? It looks new, though it must have been on something, as it had a few (rather rough) stitches on it.

If it didn't change shape, can anyone tell me which part of the Navy this badge belongs to?