grey/black water tanks

Can anyone direct me on suggestions of who can replace/repair black and grey tanks. I have a 1967 Tradewind…no grey tank and what seems to be an intact black tank. Fittings in bumper difficult to get at and no grey holding tank. It leaks onto ground or backs up in trailer. I live in Tampa, FL. Any suggestions on who can install a grey tank and approximate cost?



Thanks

Linda