I replaced the oring again today (did it a year ago). I used the OEM one.
After tightening down the bolt, i noticed there is still some play in the "flange" (not sure what to call the plastic piece). The bolt side acts like a bit of a pivit point.
The pivot was not much, but enough to notice some pressure acting on the fluids that spilled around the flange.
I'm going to order a new plastic 90 deg flange thingy.
Keep you posted.