Most notably, the 1956 Whirlpool Imperial washer and dryer set which once belonged to Chuck Dhiel. I was in Beltsville for the rebuilding of the washer and what I learned there helped me save my 1965 Lady Kenmore and 1966 Inglis Sterling washers.
More fun stuff from Beltsville - 1966-ish Kenmore 600 Roto Rack dishwasher, 1955 GE SU60 dishwasher, 1957 GE Clothes Conditioning Dryer, 1965 Lady Kenmore Dryer (converted to electric from gas), and a 1957 Hotpoint automatic washer!
Hmmmm, A '55 Unimatic (from "the farm"), a nice ('83) Whirly belt-drive, a nice Kenmore Collapse-O, an early '60's Westy Roll-Out DW, A beautiful and minty '67 Frigidaire CI Stove. Oh, and a Frankenstein Kenmore Belt-Drive from Greenbelt.