Hi Vonrd,
It's not a big deal, I was just curious.
For reference, here is the Bf 109F-2 of Detlev Rohwer, Stab I./JG 3 Technical Officer, circa August 1941:
Stab II./JG 1 would be the same, just with the horizontal bar of the II.Gruppe after the girder cross.
The circle should be as large as the chevron. Though, there are examples with the circle being smaller.
Hope this helps!