Br. Rav, you´ve got the upgraded filter cap version with 3 bolts, the old cap had only 2 and was used on the old G5s, like mine.
Unfortunately I had the wrong gaskets when I did the fist oil changes, just like you, and so the old ones were reused. I guess the new cap with 3 bolts is tighter, but after the second change the gaskets blew on my filter cap. I had just driven onto the Autobahn and was going 110 km/h when it happened. Immediately there was a smokescreen of epic dimensions, as the oil dripps on the exaust pipe and silencer. I made it barely home - crosscountry
The main oil pressure is hold back by the o-ring, the paper gasket is not able to hold tight without it. However, even if you´ve got an additional bolt be carefull with reusing this o-ring. To fit into the groove it has to be pushed over a sharp edge and may get damaged, so I recommend taking a new one each time.
Simply order 5 of them from N-field or Hitchcock, whatever continent you´re living on. And speaking of ordering gaskets, just order 2 of all other paper seals and o-rings aswell. These are penny goods and then you have ´em ready if it´s necessary. Best regards
Maturin