Agreed to the former, but I wouldn't mind a back up...to the latter, I didn't know about it!, but for sure one for the next time I take it apart.If you've put silicone on the chaincase halves you shouldn't need anything else. I can't understand why you didn't get the improved seal from the club and you wouldn't need to mess around with any of these.
Chaincase halves definitely did not have an even gap all round when fitted up and wider at the bottom edge so slighly concerning as to oil leaks.