It’s going to need a complete tear down since the former owner was too cheap to use warm water or quality detergent like Tide or any P&G detergent and more than likely is all gummed up on the outer tub surfaces and inner tub surfaces you can’t see.
It’s direct drive. I don’t think the belt drive portables ever came with a dual action agitator since the long stroke agitation from the belt drive transmissions were more than enough for that tiny tub and a dual action agitator would have been a bit overkill for the belt drive portables.
I had an early to mid-1970s avocado LK portable pair and it had a white straight vane agitator. I never saw a gold agitator in these in any published Sears ads.