Yeah I forgot to say I had no luck when using the Shield GND, had to put the NEG probe on 0V GND instead.
Retested and got the following results:-
13.80v
-14.25v
5.29v
Unfortunately, I don't have a spare PS to check
Its too late now, but, switching power supplies should always be measured while LOADED. That is, connected to, and powering the computer they are designed to run. You may have to read the rails (+5V, +12V, -12V, etc) inside the Amiga, since the connector will be plugged in. The rails should be within say, 5%, and most importantly, not drift very much.
