What to use for replacement top rails

I am need of some help to replace some rusted rails that we found when we opened the pool. The pool was here when we bought the house so we are not sure of make or model. We do know it’s a 21ft round pool.

Hello Ryno2313 - We’d be glad to assist you. Could you post a picture of the top of the top cap?

Top of the top cap.

This looks like an older Asahi pool. We recommend trying https://www.asahiparts.com/.