When I brought home my Kelvinator like this, I got intrigued and went on a scavenger hunt for information about the history of this washer. I posted a bunch of the time-line for Beam, Franklin and WCI and how they were related and came to be, but I don't think many were too interested at the time.
The Kelvinator version of this machine that I had, was made by G.R. Manufacturing in Grand Rapids, MI (the plant is still there - they make refrigeration products for Electrolux/Frigidaire...I called them ;-) and had the exact same underbelly as yours, Eddy. I thought the wash action was pretty aggressive, but rollover was no Frigidaire pulsator for sure. Though as with an early Norge, we know that rollover doesn't necessarily have to be present for decent washing results - sometimes the thrashing alone scares the dirt away!
The tub-brake in mine was the same, I was shocked at the lack of the indexing tub and the brake, but the parts info for this washer - and it's similar kissin-cousins - proved it. The brake was on the bottom of the transmission above the pulley. Similar machines were available from Gambles - Coronado, Western Auto - Wizard, Co-Op at the same time. Around this same time period, Franklin would become White Consolidated Industries (from the White Sewing Machine Company) and would start acquiring brands like Gibson, Easy, later Westinghouse and Frigidaire. I traced mine to about 67-68 as well and most of the service and parts info I found were from the same time. It looks like this was the first of the perforated tub machines, as the solid tub was still being sold until 66 or so. I think this might have been a "bridge machine" for Franklin/WCI between the solid tub and the takeover of Westinghouse in 1974 when their design changed again.
Your model number, Eddy, are similar to the "factory numbers" listed in the Co-Op service and sales book I have.