Welcome to the forum! You are at the best place on the planet to learn about these things if this is your area of interest. There is a lot to read, but some of it is repetitive, and not all of it is accurate (I routinely find errors in my older posts, because we are all learning here, continuously). In general, information that is repeated often and never challenged is likely reliable, so read as many of the archived threads as you can to separate the wheat from the chaff!
The article you referenced is mostly correct, but contains several significant errors as well.
Howard Head did not invent oversized racquets (threads elsewhere in the forum addressed this topic), but he was the first to claim IP rights to them, and not just in the US. With the notable exception of Germany (mentioned in the article you linked), his effort was surprisingly successful around the world, likely because racquet-making had never been an extraordinarily profitable undertaking; no one else had the wherewithal to challenge him. Within the industry, this patent was seen as a logic-defying travesty, and had the immediate effect of stifling innovation and competition among the manufacturers, pricing the smaller players out of the game entirely, while compelling and accelerating the wholesale shift of production to Asia. The latter would likely have happened anyway without Head's push due to many other factors, but it most definitely made low-volume production a guaranteed money-loser everywhere except in the Far East. So no, Howard Head was not seen as a genius or hero by people who made racquets for a living.
The Prince/Head patent covered string bed sizes from 85 to 135 SqIn, not 95 -135 as mentioned in the article; so yes, Wilson had to pay Prince a share of their take for every PS85 sold, and for pretty much every racquet they sold after they discontinued the last of their standard-sized frames until the patent expired. While Wilson was not happy with this arrangement, it was tolerated based on the assumption that Prince's aggressive enforcement of the patent claims around the world helped to reduce the field of competition and raise the entry barrier; both of which were beneficial to Wilson in the long run, all for an annoying but ultimately predictable and affordable cost.
Other manufacturers, including Howard's eponymous company turned competitor, tried to circumvent the patent initially by making weirdly-shaped frames, such as the snow-shoe-like offerings that were narrower than the minimum width covered by the patent, or the slightly sub-85 SqIn midsize models with enigmatic fractional specifications (84.5 SqIn head, 23.456% larger sweet spot, etc). It's not that racquet engineers and marketing people had suddenly developed an aversion towards integers, but because the in-house lawyers thought this was necessary to keep their Prince counterpart at bay.
Howard Head most definitely did not invent graphite racquets. When he was still running Head, he had an opportunity to produce the earliest compression-molded synthetic racquet in the world but chose to forgo it in favor of his own aluminum sandwich architecture. The earliest commercially available graphite racquet came out in 1973, though the first wave of compression-molded graphite frames were launched in 1975, slightly ahead of the aluminum Prince. At the time, Prince was strictly a ball machine-maker, as the article correctly pointed out. Prince's racquet projects were farmed out to other manufacturers. The original aluminum frame was first made by Maark Corporation using ALCOA-sourced alloy, and eventually by Kunnan in Taiwan using imported and (later) locally-sourced alloy. POG was developed entirely by the R&D staff at Fansteel’s sports equipment division to Prince's size and durability specifications. It was a scaled-up and reconfigured Tony Trabert C-6, which was already 4 years old by the time POG was launched. Howard Head was responsible for POG’s size and shape, but nothing else.
The racquet pictured in your photos is a very late US-made example that dates to 1982-1983, when production was being shifted irreversibly to Kunnan. This sub-variant is actually not very common, as most of these individually-grommeted POGs were made in Taiwan.
Elsewhere in this thread you will find examples of the earliest Fansteel-made POG and its Grafalloy-produced successor, both of which are considered first generation by collectors, but are visually quite distinct due to their very different grips and other cosmetic features. Check them out, and good luck with your hunt!