"unknown history should be disassembled, cleaned, and refilled..."
Well yes, suppose in a perfect world that is what "should" be done, but then again maybe not.
First and foremost not everyone has the proper tools and skills to do such a job. Next you have to source the parts. While there is still quite a lot of NOS Maytag wringer parts floating around out there, not everything is dirt cheap.
The other common enough option back in the day would be to call the "Maytag Repairman" and let him do the job. Well depending upon where you live, good luck with that. Many of the old timers are either retired or dead. Young guys often don't know much or anything about Maytag wringer washers.
This leaves you with the final choice, packing up the thing and taking or shipping it to the few places that still do this kind of work. Phil in NY, the Amish etc...
Probably the best thing is to find a unit that does not require a huge overhaul *yet*. There are literally scores if not hundreds of Maytag washers all over this country. Since Maytag only ceased production in the 1980's you've still got a decent supply of rather "new" machines out there. If they have been properly taken care of and given routine service a total breakdown and cleanout of power unit and so forth shouldn't be required up front.
When buying a Maytag wringer you have to know what to look for; the things were so over engineered and over built that they could and sometimes did run for a long time with water in the gear case and or various other issues. Some people simply used the heck out of the unit until it finally died.