Indeed, that power nozzle was made by Ryobi for one of Singer's last power nozzle canisters. We had these Singers in Canada in the 1980's methinks. I seem to remember them in Consumers Distributing Catalogue stores.
Never saw a Kenmore version, but Singer had a history of making uprights for Sears, so it makes sense that they might have contracted a nifty canister from Singer for their Kenmore line-up.