Adding a handrest for Petzl/Charlet Moser Aztar

I climb with a pair of Petzl/Charlet Moser Aztars

and want to add a handrest to each tool, and was curious if this would fit? If so, would it fit more snugly with the Sum'tec or Quark/Nomic/Ergo model? Also, maybe a dumb question, but that price is for one handrest, right? So I'd need two.

Also, the reviews say it breaks easy, does anyone have experience with this? If so, is there another solution?

Or are you trying to make some sort of hook at the bottom of the grip, like the Griprest that was available on the 1st generation Quarks and the Fang for the original BD Vipers? We're talking 15 years ago for those tools; neither of these pieces are available and likely wouldn't fit anyhow.

Primarily, a handrest at the bottom, but yes, potentially an upper hand position too. 

I know they're old (it's what I could afford as I got into ice climbing) but was hopeful that a solution existed.

What do you think?

http://christofferseventyr.blogspot.com/2010/02/how-to-modify-petzl-aztar-for-leashless.html

Google "petzl aztar modification" for more, it's pretty common.

I saw someone create an upper grip by cutting up an ice clipper to a j shape and simply taping it on. Didn't look too bad for a $6 retrofit. 

People use to use the original quark lower rest and shave a little bit off the Aztar handle at the bottom to make it fit. I'm sure you could find some on the internet still for sale