Total Power loss

I proudly own this German beauty. Unfortunalyit isnt running. Looking of some one who may possibly have a solution to my problem. Here is the situation. I bought it from an older couple a few months back. The recent history of it is that it was running. Last driven from Texas to Cali and back. Stopped at the gas station for a fill up. Brought it home and parked it in the yard. 2 months or so went by with out being driven buti was started on a weekly bases until the husband got sick. After another month or so I bought it. Put a new battery in it and it wouldnt start. The engine turned over just fine though. So i changed the spark plugs, wires, rotar, and distributer cap. Still turning over but not starting. Added B12 Chem-tool to mix gas in tank. Moved the car to a garage and at that point I lost all power. No head lights no door chime. Nothing. Now i need help finding and figuring out what could have possible gone wrong and also how it can be corrected.