Evening all, newbie signing in.

[KermitLeFrog]

I would get rid of the dowty, SS flat and spring washers. The important thing is to stop the bolt moving in the CCT housing. I would use loctite on the bolt into the CCT housing (which acts as a sealant as well) and then on the lock nut to hold the bolt firmly on the CCT housing. Add the second lock nut if you want but it's not doing anything important (just stopping the bolt screwing in). All these washers are just giving the bolt more opportunity to move.

(Disclaimer: I'm a professional mechanical design engineer)