Gogen was very highly respected in japanese karate, and very little in okinawan karate.
Nevertheless, I own a copy of the $100.00 book (no 0997) and I concider it a great book (expensive but great). It is clearly illustrated and easy to follow -unlike several of other books by the old masters.
It is a especialy interesting book for me as a kyokushin student, to look at the striking similarities between kyokushin and the goju it in part was based on.
Gogen may have played a bit with the truth on occation, but he was hardly the only one of the old masters who did that. His karate was very good. Not identical to okinawan goju, but good.
If you can find them, I recomend you to read "What is karate", "This is karate" and "Advanced karate" (esp the last two), by Masutatsu "Mas" Oyama. Unfortunaly all of them are rare and expensive.
"Tote-jutsu" by Funakoshi and "Okinawan Kempo" by Choki Motobu are also good, but in my opinion they are not as clearly structured, and not nearly as well illustrated. Mostly because they are much older, but still...
Never seen the "blue book" of Kanei Uechi, but now I will look for it.