Is it iron or aluminum?

Here is the nearest to your piece that I could find. Its a cast iorn garden bench with grape design.

Garden bench, cast Iron, Grape Design

Here's what happens to these old cast iron pieces. I need two replacement legs and they need to have mounting for the stretcher. These are rear legs for a chair. For their original owner they came as a set and assembled with nuts & bolts.

Couldn't open JD's link. Is my only hope to canibalize other chairs? I think that the stove co. went out of business. These were common at one time, does anyone know anything further?