This ISI Sports Sovereign II is clearly from the early 1980s mid-size wood manufacturing era in Taiwan, given that handle join piece. There is no country label, but the positioning of the Taiwan patent as first in the list is a confirmation. The 366g 32.5cm balance specs make this probably the lightest Taiwan mid-size wood I have tried, but it still feels solid and stable, and shows no warp.
What is particularly interesting is the 'layup' diagram showing the graphite as a continuous structure with thick facings on either side being joined together internally. It looks rather more complex to construct than the simple graphite lamination or graphite facing you usually see. I scraped off the flaking paint one side of the hoop, to confirm the largess of graphite.
Was ISI sold globally? I have only seen them in UK magazines. They also produced a rather nice looking Golden Sovereign wood with a full graphite face, similar to a PK Golden Ace, as well as various graphites.