16" Fuch centre caps

[paul_f]

I am in the process of purchasing a pair of 16x6 Fuch wheels without centre caps, I already have a pair of 15x6 late Fuchs and I have 6 centre caps, 2 have 3 prongs on them and fit my 15x6 wheels, and the others have a metal band with 3 tabs in it which fit a pair of cookie cutters I have.
What I need to know is if I need to get another pair of 3 prong centre caps, or whether I need to keep the other set.

Thanks a lot
Paul
(UK)