Hi there and welcome to the forum, Cant help with the bars as I dont know your shops in Oz, but shouldnt be too difficult to source some, have you looked at Wemoto. Anyway as for the brake, you should be able to push the little actuating arm on the backplate and it should return under the infuence of the springs on the brake shoes, if it feels very stiff, then it is no doubt seized up in the hole, if this is the case you wil have to strip it down and clean and grease the the brake cam where it passes through the backplate. before you strip it down, mark the actuating arm in relation the the splines that its on so you get it back in the correct place.
...Paul