It dont look quite like the IYE mast I have, a 1980 model. Perhaps an earlier model? Our mast have a IYE sign riveted to the front of the mast. Aft beam looks very IYE! Halyard hook is different as is the mastfoot. Spreaders looks like they are set up for pre-bend? We drove with pre-bend on our IYE section for some time and was happy with it.
It is easy to spot a pre-bend setup. Spreaders are raked well aft of the sailtrack.

Prebend was invente before my time in the class, but I also believe it was in place for the 84 games.