@donalds ,
Sounds like your on the right track with very little gasket sealer.
It makes cork gaskets slick and they mush out.
As for the metal inserts my guess is they were deleted to cut manufacturing cost and increase profit... (Never heard of corporate America doing that)
100 inch lbs is not a lot of torque as you well know. Do you have an inch pound torque wrench in your toy box?