Basically you can ignore 99% of the quest and head straight to where Dawson is located, he will be there and just kill him ( much easier to do than killing 2 rogue sentinels simultaneously ) get the holotape and activate his sentinel.
Sentinel is nearly invincible and single handled all the raiders in that Federal ration stockpile nearby with just stock equipment.
Red is weak.
With end game gear he can even single handle Libertalia while tanking the fatman nukes like a true champion.
By the way even if you ignore the 2 rogue sentinels they won't despawn once the quest is completed so no worry on missing those T-45 suits.