Can't really make a judgement call on the lines without seeing them, but if its just surface rust on the lines, just flush them. but if the lines are pitted and scaling replace them. Also, when you try to remove the lines at the fittings, chaces are you'll round off the fittings. Then you'll try to get them out with visegrips and you'll brake them off in the calipers. Then you'll try to get the broken pieces out with an ez out. Don't waste your time. Buy all new stuff.
In my opinion, the brakes are THE MOST important part of the car. If you're doing a true restoration, don't mess around. Go ahead and buy new master and slave cylinders and new lines, especially the rubber lines. Might as well get new rotors and wheel bearings too. To do it right, you'll also need a double flare tool. Never use single flares on brake lines.
OTOH, if the lines don't look too bad, especially at the fittings, buy you some special line wrenches. They can torque the fittings loose without rounding them off better than regular open end wrenches. A day or two before you try to loosen the fittings, spray some penetrating oil on them. I think Kroil is the best penetrating fuid on the market.