We already know that the Boss Book (and the CE-2 page on this site) is wrong when it states that the CE-2 production ended November 82 but how wrong is this claim.
Is it absolutely certain that that's the original backcover? Not suggesting that every MIT CE-2 has an unoriginal cover, but getting the production completion wrong by 8 years seems doubtful.
I've got a MIT CE-2 with a AA58556 S/N, which is August of 1989. It's the white sticker in the battery compartment that says Taiwan on it, so I'd guess it to be original. The one on ebay has the newer silver sticker on the bottom plate, which could be non-original. If it is original, it's the newest CE-2 that I can remember.
I've got a MIT CE-2 serial no. BB67242 on the bottom plate. It's in mint condition with box and instructions and also a blue Boss sticker sheet (one big sticker and two smaller ones). What's interesting is the instructions have got "Printed in Taiwan Apr. '89 H-3" on the back. I'm pretty sure I've seen a CE-2 on eBay with a serial no. where the second letter was C.
The easy mistake is that they meant 92 when they wrote 82 but the CE-5 was released Nov. 91 and perhaps it was released while the CE-2 was discontinued. Then again perhaps it was discontinued at the same time the CE-3 production stopped in Feb 92. There's many possibilities but it really looks like the book author missed with 8 years or more.
My observations indicate that they started using serial numbers with tiny letters June 90 (B5) (possibly B4). Not sure how long it lasted for but it was at least until May 91 (C6).