Dreaded lid leak on new master cylinder...ideas?

66 dart, recently swapped into disc up front, drum in the back.
Foolishly I assumed that the brand new dual well master cylinder would be leak proof, at least at the lid.

I got it installed and finally got it bled after 10 times, and now I see leaking coming from the top, and is nicely rusting the metal. The bail keeper is pretty tight already, I have to use a screwdriver to pry it on/off. The rubber gasket seems to not be able to fully seat/seal and getting lots of leakage mainly from the front of the lid. Has anyone figured out a fix for this?? Other than removing it again and filing down the mating surface? I prefer to not remove it (ever again). help
look at this horrible pic. this is 3 days old.
I just took it for a spin, and then looked at it again and fresh fluid was all over the upper fron portion of the MC, running down from the lid. All fittings are leak free.View attachment 1715302834
I haven't looked at one in years, but it looks funny to me. I admit I could be wrong, so don't roast me too bad. Is the cap on backwards?