I'm in the same boat JD50
Here's an idea I'm going to try:
I got the wild idea that I could form my own poly head to use for a maul. Drill a hole in it and fit it with a hardwood handle. I confirmed a process on YouTube on how to recycle plastic milk jugs
by cutting them into strips, grinding them in a blender, then melting them into a mold. The material is high-density polyethylene (HDPE) or No. 2 plastic.
I saw one craftsman make a head for a jointered mallet and although it was smaller than the wooden one he has it was heavier due to it's higher density. Pretty cool.
So, I'm saving plastic jugs of this type (and asking friends to save theirs for me as well), I'll grind them up, melt them down (melting point 248 to 356 F (120 to 180 C) in a mold,
finish it off with some sawing and sanding, drill it and fit it with an oak or hickory handle. Sounds like it might be weird, er, fun.
I'll try to keep you updated on it. Wish me luck