Added an image of album shrink wrap that included the Union Jack and "Specially Imported From Great Britain". I bought this in Southern California probably in late 1979.
It was distributed openly in the United States. My copy still has the "Jem Records Import" sticker on the front shrink wrap. I think I only played it one time (in 35 years), and stopped buying Beatles records totally after this. (no CD's)
"Rare" is relative. Nothing the Beatles did is really rare, but this is, for example, the only place at the time that the original version of "Across the Universe" could be heard, except on the original various artists benefit LP. "The Inner Light" you would have needed the original "Lady Madonna" 45 to hear, and so on. The should have called it The Beatles Relative Rarities!
It was possibly the only LP that carried both German-language versions of I Wanna Hold Your Hand(Komm, Gib' Mir Deine Hand, which translates back to English as Come Give Me Your Hand) and She Loves You(Sie Liebt Dich, which translates back exactly the same). Also here are the four cuts from the British Long Tall Sally EP but not in the order as they appear on the EP.
I think some record shops broke some sets up and started selling the Rarities LP as an individual item, in spite of the "not-for-sale" warning. This may have forced EMI to issue the record as a compilation in its own right to get around that situation. But hey, I'm only guessing!
Originally only available with the box set The Beatles Collection, where it had a not-for-sale thing printed in the corner. The LP was then released in its own right - much to the annoyance of fans who'd forked out for the whole box!