Hi Jacco,
Thanks for that.
You highlighted a key issue with my original post - this is an original A-180, not a re-badged A-180.1 so that probably explains the earlier PCB layout.
It was clearly sold originally as a 2 x 1:4 because there is no black line on the panel between jacks 4 & 5.
I deliberately got a cheap, second-hand one in case I made a mistake when re-instating the solder bridge.
It will also be easy for me to remember that the ( one and only ) A-180 will be my 1 x 1:8 and my other A-180-1's will be the 2 x 1:4's.
Looking at actual track on the PCB ( in two halves at the moment ) one ends at a solder point and the other ends at one of the pair of tiny holes so I think that these two need to be joined with a new bridge.
From the bodies of each jack, it's difficult to tell which two are the Tip and Sleeve and which two are just legs.
Cheers,
Nick