Hayward SP 712 Valve, rebuild or replace?

Well, i'm into my first real summer of pool ownership. I noticed a water leak in the top of my valve assembly, along with a tiny trickle of water out of my backwash discharge when i'm in filter. I have no idea how old the valve is. The pool is about 30 years, if the date in the sidewalk is right.
Should I look at a rebuild and get more life out of it, or should I just spend the money and get new? I hate to spend twice, but money is always tight. If I replace it, does it have to be an exact replacement?
Thanks!!