@S0nic
Your Amiga is not exactly an A500+, it uses the same rev8 motherboard and custom chips as the A500+ but it has been factory configured without half the RAM, without the Real Time Clock and without the capability to add 1 MB chip RAM on the trapdoor slot, so essentially it has been brought down to plain old A500 specifications and was actually sold as such.
So it's best to think of it as an A500 and not as an A500+. Commodore certainly believed so

(it's a potential A500+, if you like, but you must install all the missing components before it becomes an A500+).
Accordingly, as it was shipped with KS 1.3 (A500+ was never shipped with KS 1.3 btw), these manuals are correct.