quite possible because it's from Europe, but remember that Apple was sticking + on the end of their model names 6 years before the Amiga existed.
Did they? AFAIK, Apple always used “Plus”, not “+” (see https://en.wikipedia.org/wiki/Apple_II_Plus, https://mirrors.apple2.org.za/ftp.apple.asimov.net/documenta...), and “+” is shorthand invented by the community.
The Macintosh Plus, similarly, wasn’t a Macintosh+ in Apple’s marketing, AFAIK.
And, looking at https://en.m.wikipedia.org/wiki/Amiga_500#Amiga_500_Plus, it doesn’t look like Commodore stuck + on the end of their model names, either.
/s
/s
/s
(joking, relax..)
https://isaac.lsu.edu/byte/issues/197710_Byte_Magazine_Vol_0...
A quick search doesn't find me pictures, but I did find a "Vector 1++”:
https://chrisacorns.computinghistory.org.uk/Computers/BBCB+6...