I need a Building Engineer's professional opinion

I'm on the building committee of a small 3 story 1960's apartment building with two entrance foyers, each with 3 stairwells. These are the only access to apartments on each floor. Six original (we believe) fire doors are located on both stairways at each floor and remain open always. There is no identification on doors or their jambs relating to fire proofing and most door handles don't work. We wish to remove, and not replace them but require a professional assessment that this can legally be done and new doors will not be required.
Photos can be provided but not available at the moment