Help, my Mag Motorsacoche 1026 SLR X is missing a condensor?

I have just bought a Ransomes Vergecutter with a Mag Motosacoche 1026 SRLX 313 engine but no condensor inside when I opened it up - a coil, points but only an empty where the condensor should be. I sent away for one giving engine specs etc but the condensor I got back was like a small battery without any wire coming out to attach to the points or wherever. So it must slot into something but that's missing in my engine. Does anyone know how it connects in. Has anyone please got a diagram of how the electrics work or a manual that they can scan in. Desperate!