The little fabric softener cup
Unfortunately, during agitation, especially if a regular sudsing detergent was used, the foam came up through the outer part of the dispenser and through the little slots at the top of the cup to mix with the softener. Of course, with what turned out to be the default use of the cup, the dispenser was not rinsed out so a pretty healthy deposit of softener residue built up in the outer assembly and that probably served as a suds killer thwarting the migration upward. Who says ignoring a problem won't make it go away?
I think you will be very happy with the Power Fin in the 700. Not only are the fins shaped for better turnover with their downward slope, but they also will really push water against that unperforated section of the tub that would have been opposite the high fins of the Gyrator. Instead of letting the currents escape through the perforations in the newer tub design and into the outer tub, this tub starts the currents up the wall of the inner tub, really lifting the load up to the top. Then the design of the fins at their juncture with the barrel is much more effective at getting clothes down into the washing zone because they are higher near the barrel and lower at the outer edge of the skirt. If Maytag had left the tub alone, they could have had some real wash action. Fortunately, we can combine the old tub design with the Power Fin to get what Maytag missed.
The stainless steel filter and dispenser housing show up on eBay from time to time. That nice Maytag man in NY who sells Maytag conventional washer parts on eBay might even have one.