1970 Buick Electra 225 Convertible

I recently inherited a 1970 Electr Convertible from a dear friend 0f 38 yrs who passed away 2 months ago. His son gave me car since considered me family. I am very excited about this opportunity but have no clue where to start. Car has been sitting in barn since 1999 when it was last driven and was told parked because of hole in gas tank. It is so dirty I am unable to take pictures of it tell it is cleaned up a bit. Body is straight with smal hole in trunk floor and little rust on right front fender. Was told by my brother to flush all fluids, replace tank, new battery and carburator kit, plugs, wires etc before starting. Any other ideas for future appreciated. Won't get title untill lawyers finish up estate.

Check the brakes. Probably needs entire overhaul of the brake system. I would not do anything until title is in your hands.

I HAD 1969 BASICY SAME CAR   HAD 430 CI,  U HAVE 455 CI.     I WOULD SPRING FOR NEW GAS TANK      BUT POR 15 IS LIQUIDE TO COAT/SAVE OLD GAS TANK      GREAT CAR BUT ONLY WORTH 25,000 SO WATCH HOW MUCH U INVEST.     A GOOD CAR BUFFER KNOW HOW TO SAVE MOST ORINGANAL PAINT JOBS.     ORIGNAL WORTH A LOT MORE

My mom had a '69 Electra 225 4-door I'd ride in as a kid and teenager. I think I'd put a bit of oil in each cylinder, by removing the spark plugs one at a time, and then try to turn the engine by hand by putting a socket wrench to the crankshaft pulley nut. Actually it's best to leave the plugs out if trying to turn the engine by hand because it makes it easier by releasing the compression. Keep track (ie label) the plug wires if it helps to keep them from getting mixed up as to where each goes. This to make sure the engine is free turning before using the starter. I also might remove the starter and bench test it before actually using it on the engine. Starters can get frozen after sitting many years in my experience.