A few years ago I bought a NOS F3 Premier A-B-A set locally; it ran good. I started with problems after moving and starting it up on my new layout. I needed a new wiring harness between the Trailing A to B unit and discovered my 10 position harness is no longer made. The down loaded parts diagrams with parts lists call out 4 position connectors. Some of the PS2 engines for sale on Ebay clearly show a 10 position (2X5). The pictures in operator's manual I got with set are not clear regarding the connectors. Also the pictures of the lead A shown have much fewer wires bundled over the mid-position battery.
Charlie