Garry,
I don't know about production run numbers for the "1+1" version of the October cassette, but it was only released in the UK and Ireland as far as I'm aware.
Patrice's site has a picture of the cigarette-style case, anyway (scroll down to the UK * cassette heading).
So was this a trend for a while, leaving one side of a cassette blank? Would this mean that you could accidentally tape over the A-side? Or did they somehow write-protect one side only?
The pack of four singles with numbers on the front is almost surely
U2 PAC 3.
A nice item, to be sure. There's a few up on ebay right now if you want to get an idea of what kind of prices they fetch (looks like on average around $50 USD for a complete set in nice condition).
Hope this helps...
-Rob