Keeper for 82-226 latch

It's hard to say. It really depends on the space available in the door. It's strange that there aren't even any holes where an old keeper could have once installed. Has your door always been unable to lock?

I would start with the three keepers related to the 82-226 on its store page. These are commonly used with this mortise lock, but to be honest they're just a jumping off point. There are a bunch of different keepers that may work. I would carefully go over the measurements we show to confirm they can fit in the space in your door.