Keep the tank. It is a real unique design with good lines. When you sit on the bike with that tank, especially if you have a smaller seat, it is something special. It is also the tank that belongs to the bike. Wire wheels too, very cool. The T3 was a very high quality standard bike, what other machine came with stainless mudguards, allow wheels with stainless straight spokes on Borrani rims as standard? No cheap crap.
Get the bores changed if they are still chrome, and get it running. You'll get a better idea of what needs changing as you live with it. If you're used to Japanese fours this will be different but really engaging.