My daughters 69' fastback has been sitting in a shed in victoria for over 5 years. After an engine rebuild I am going to drive the car to queensland but after a few laps of the block I find the brakes are grabbing constantly (probably rust in the drums) but when I put the car back in the shed I noticed the front left wheel was very hot so I'm guessing the calipers are seized. So my question is, am I better to replace both front calipers and rear wheel cylinders and flush fluid ect? Any advice is appreciated

At the very least i would be flushing the lines but with such a long drive i think it would be safer to pull them apart and replace anything that needs to be.