Figured that I should update this thread since I found this sofa in a Metropolitan Furniture ad page, and also have seen a matching chair with a paper tag with Metropolitan Furniture's Registry number on it (CAL-1745). The sofa dates from no later than the early 60's.
The designer is not yet known, but the most likely candidate is Jules Heumann, who did most of the design work for Metropolitan in the 60's (and may also have been the owner of the firm). As Kasparian was also a California designer, there is a chance he could have done work for Metropolitan, which was based out of San Francisco, with a manufacturing facility in Pomona.
If you need any help, please contact us at – info@designaddict.com