53 Chevy Bench seat support or riser??

[jd.marshall]

I'm looking for the stock bench seat support structure that is part of the floor pan. I have the bench seat and frame but the support was removed to install bucket seats by a previous builder and I want to go back with the original bench seat arrangement.

Know where I can find this assembly for reinstall action to my floor pan?

Maybe this is referred to as a riser but I still can't find one in any search