I refabricated all four of the spreaders from my '69 32 about six years ago using a slab of sitka spruce from ML Conlon in White Plains, NY. If you search my postings you'll find my summary of the job. I'm not a woodworker by trade but with a borrowed planer, band saw, and router they're quite simple shapes: trapezoids with some of the edges routed nicely.
I coated the new spreaders with unthinned epoxy, drilled the holes a little oversized, filled the holes with thickened epoxy, and redrilled the final holes. I haven't had the mast down since but I think these will last a really long time.
Once you go aluminum you're opening up a Pandora's box of customizing the fittings to hold them to the mast. Tough to justify the effort in my book, never mind the cost.