The cranks are GPM, and the wheels are indeed 24". The story the shop was told is that it was raced by a junior who outgrew it, and the current owner rides it regularly! I am not sure of the fork crown but can ask a friend of mine to take a better photo. As far as the date goes, the shop got in contact with the builder and he dated the frame based on the decals. Wether or not the parts were added later I am not sure. Also, it has a really nice edco competition headset!