TOPIC: help with controls for a mark 35a

hi everybody. i recently acquired an old evinrude boat powered by a mark35a. the controls are all there but do not work quite like mint.....
what are my options on controls? i saw online that replacement cables are available for about 20 dollars each but is there any for my dual lever box? i would prefer to keep my box as im trying to keep most of it original. and what about steering? its a side console boat so both cables run on only one side. any specifics on making it that part work correctly?