arm rest foam?

I think my lincolns arm rests are the originals, appear to have all been painted black by someone though. The plastic on all of them is good but some of the foam arm rest section is cracking and falling apart. I figured I'd have to find new ones but think I could just fine some stiff foam shape it to the shape of the originals and cover in vinyl?

Any idea where I could find a foam that hard? only thing close I've seen is the green foam sold at joanne fabric for chairs I think that stuff would be too spongy.

 

You need a foam called "Insolite" It's a closed cell very dense foam. I stock 1" thick. I use it on custom bike seats and rod armrests. It can be shaped easily with 36 grit paper or a body filler cheese-grater. The stuffs not cheep though. PM me with your email and the size of your armrest and I will get you a cost.