Hi Cody,
I posted on the Facebook forum but will comment here as well.
Do not weld repair a tempered aluminium section, you will reduce the strength by up to 50% if you do.
The best alternative is probably an internal or external sleeve about 10% longer than the mast both above and below the damaged area. If the two pieces are slid together and sealed at the bottom then the gap can be injected full of low viscosity epoxy, which will marry the two parts together and give you a mast stronger than the original. If you use an outside sleeve the join at the top can be smoothed with an epoxy and fiberglass bandage, faired and painted.
All the best with the project, she looks like a great boat.
David.