I ordered armrests for my '54 from Classic Parts ... I didn't use their template, I made my own from the door itself, but the problem I had was with the plastic parts of the armrests. I slammed the door one cold Winter day and the armrest came off in my hand! The cold (thin, cheapo) plastic broke!
I thought the plastic looked pretty hefty at first ... but after it broke and I looked at it, it was *really* thin!
I wound up fabricating my own parts from red oak and covered everything in elk leather.
I'm much happier now.
You can see what I did
Here PS - I dunno about the armrests for a '56 but the armrests for a '54 "hang" when they're mounted! You can see the details about this on my page (linked above) ... they make the armrests for a 90-degree angle but the door on a '54 is angled where the armrests mount, so you wind up with a tilted armrest! I fixed that problem as well.
