Not really sure where you're going with this thread, but this info from Wikipedia might help you:
Although officially introduced in 1992, some Amiga 500 Plus units had already been sold (masquerading as Amiga 500 models, and with no prior announcement) during late 1991. It has been speculated that Commodore had already sold out the remaining stocks of Amiga 500s, before the run up to the profitable Christmas sales period. In order to make enough A500s before Christmas, Commodore used stocks of the new 8A revision motherboards destined for the A500+. Many users were unaware that they were purchasing anything other than a standard Amiga 500. Although the Amiga 500+ was an improvement to the Amiga 500, it was minor. It was discontinued and replaced by the Amiga 600 in summer 1992, making it the shortest lived Amiga model
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http://en.wikipedia.org/wiki/Amiga_500_PlusSo you've got an A500+ motherboard that was downgraded to standard A500 spec, or never outfitted fully with 1MB chip, the battery, or KS2.04 ROM. You'd probably need the standard A500 1.3 manuals to have a complete set. Should be plenty of those kicking around, good luck!
