Locating tab oil pump?

[Deadduck]

I have just done a rebuild on my engine have put full bottom end back together and have forgotton one of the location pins on the oil pump one side is in just not the other should i pull sump off oil pump off and put in? and reseal? I put a new metal gasket on can I reuse that or do I have to buy a new one? The one on the right facing engine is in.
Thanks