That style rub-rail was made local by a company that is no longer in business, but I think it was a copy of another manufacturers product at that time? I would suggest the newer style w/insert, and replace it all.
If its the same as the 89 Baja one solid piece. I replaced mine with a Black Taco semi rigid piece 1 7/8. This was just about identical. If you need a model number I will check the box I have for it.