Door arm rests

I just picked up a 2006 PreRunner SR5 Dual Cab Long Bed that I'm now in the process of fixing up. The front door arm rests have cracked under the fabric. I'm finding plenty of vinyl replacement kits on eBay, but they're only the cover, not the underlying structure. Anyone either a) have a source for the actual armrest piece, or b) have repaired them? I was thinking about using an epoxy putty like PC11 to repair the cracked substrate from the under side, or possibly use the PC11 to secure some underlayment to reinforce the arm rest.

 

Subd

 

https://m.youtube.com/watch?v=yjhYKzE_yBg


https://www.tacomaworld.com/threads/how-to-repair-replace-door-panel-inserts.569634/

https://www.tacomaworld.com/threads/door-panel-armrest-repair.94635/

 

Unfortunately, if I'm not mistaken, the substrate is polyethylene or polypropylene and there's not much that will stick to it, long term. You could give it a shot but I don't think it would hold up.
I hate to sound like a wet blanket but you'd have better luck with a mechanical support of some type, like a thin plate of steel riveted to it.

 

Thanks for the links and info. Looks like there's a ton of helpful info on this site!

 

I used fiberglass and it's so strong I can put my whole weight on the armrest.