I've just managed to save the packaging from the waste bin and have pieced them all back together. I'd rather not go back and change them, so if mono is possible great, if not ill change them.
Bin back down to maplins and changed the mono 3.5s to stereo, it has no info with them so im not sure which is + and - one pin is copper and the other is chrome, does that mean anything? also I'm guessing that the huge pin on the side is the ground?
Just match them up to a sterep plug and a DMM. From the front of the plug the contacts are, left channel, right channel, ground so the socket is reverse with the ground closest connection to the front, then right channel, then left channel.