Repairing broken epoxy interface on aluminum
If the original part is aluminum, that implies a home-made aluminum part would be of sufficient strength. You can use the existing part to create a sand-casting mold. The epoxy repair should hold your existing part well enough to create the casting mold, which would then be filled with molten aluminum.

One might consider that aluminum casting is not quite a home skill, but there are many instructables to cover such activity. If you have a makerspace in your area, you may also discover that a member has the necessary forge and perhaps the casting sand and mold material as well.

Here's a link at instructables.com to provide some background:

http://www.instructables.com/id/Learn-to-Do-Aluminum-Sand-Casting/d