After Mashmakhan folded in 1971 (their second LP The Family did not fare well), two former members - Rayburn Blake (guitar, vocals) and Brian Edwards (bass) - formed Riverson with vocalist Franki Hart and Graham Lear on drums. Their self-titled album was released in 1973 and sounds like they took off and hung out in Laurel Canyon for a while - one description is “folky-based harmony pop”¹ which I find to be a pretty apt description. A Sunday afternoon album perhaps (could be followed up by some Ptarmigan).
Here is Winter Garden:
¹ Vernon Joynson : “A Potpourri of Melodies and Mayhem (Latin American and Canadian Rock, Pop, Beat, R&B, Folk, Garage, Psych and Prog. 1963-1976)“