Looking to replace this part

That's a base plate for a patio glass door lock. We do sell a base plate similar to yours, but it's a lot skinnier and won't be compatible with the handle itself.

Instead, I recommend our complete 82-080 handle set. This is also a lot skinnier, but since you'd be replacing the whole thing it won't matter. I am very confident that you can use this to repair your door.

We also sell the 82-081, which is the same thing but with an exterior key lock.