KDS21 for sure!
It looks like it has the original 21 series wood grain or brownish control panel. That was the earliest version that Hobart came out with. The Monterrey was the same unit with the black control panel.My aunt and Uncle had this same machine and they purchased it in 1984.
While it is a great machine, just be aware that there is nearly nothing available for it from Whirlpool anymore except the very most common to later model parts. The weak link in it was the wash arm support/filter assembly and they are NLA from Whirlpool.
Some of the members here have spares for it, including myself but I also have a working 21 and 22 and the mechanical parts are mostly interchangeable and I just sent a spare filter assembly to my Uncle in AZ who has bought a home that has a ISE Classic Supreme which looks like a KD20 series control panel but has a 21 Series pump in it but the support is shot.
If it were me, I would want to see it fill and run and make sure every little thing works in it. It may be worth buying and parting out!
