I bought an Incra and am very happy with it. Being able to adjust and repeat a measurement is invaluable.

There are a quite a few aftermarket fences that could be adapted to work with your saw.  Biesemeyer used to be the standard to judge by, but there are probably other brands that work just as well.  Fences aren't cheap - depending on what you plan to use the saw for, hunting down replacement parts for the existing fence might be worthwhile.

I've never been a fan of all the guards installed on table saws these days - I prefer good practice over putting my faith in the mechanical contraptions, but that's just me.

There are plenty of fence choices to choose from. A couple hundred used to get you one from grizzly bo idea of the cost now.

A saw that old won’t have a riving knife. They do make riving knifes that are part of a zero clearance insert if you want one.

Personally  a riving knife is something I insist on now. Used to hate safety crap on saws but now that I’m cutting more hardwoods every day it makes life much easier.

Years ago I used clamps to stabilize my first tablesaw fence.

You can retrofit to newer style rails when you upgrade the fence but a saw that old didn't have a riving knife. As a prior poster said it would have had a guard and splitter with anti-kickback pawls.  You definitely do not want to run a saw without at least a splitter if you don't want to take a board to the teeth when the kerf pinches up.

There are many fences to choose from depending upon your price point. Vega gets really good reviews but several of the others mentioned are also very good.

People can and do produce quality work from a contractor-style saw and they are much easier to move and store than a cabinet saw.

That being said, if you are really going to get into woodworking you will eventually find yourself buying a cabinet saw.

What works for you sort of depend upon your goals.  The Rockwell might well be easy to repair and is way more solid than a contractor saw.   Table saws are pretty simple and provided the motor is strong, table flat and the lift and tilt mechanism isn't damaged it can likely be repaired fairly cheaply if you can find or retrofit parts.

New saws will have better safety features like a riving knife which isn't inherently any safer than a guard and splitter (when used properly).  Riving knives are  a hell of a lot more convenient though because you have to take off the guard every time you want to do something where you have a fixture like a crosscut sled passing over the blade or you are not doing a through cut (e.g. dado blade).  

However, even new saws won't come with a super-premium fence like a Vega or Incra.  The least expensive cabinet saws like  Shopfox and Grizzly (which are just about identical aside from paint color) will come with a serviceable fence.  You could always fix the old saw and then if you wanted to upgrade take the new fence off the Rockwell and put it on the new saw.  

So, if the saw only needs a few fixes you could have something that might be more accurate than most new saws by retrofitting a good fence.  You would need to make sure to fix, find, buy a blade guard and splitter and actually use them appropriately to avoid seriously injuring yourself though.

check this out

If it can be made to fit, this is what you should get

I bought a Vega U50 and put it on a craftsman contractor saw and I absolutely love it!

We used to just buy old used Biesemeyers and bolt em up to Delta contractor saws to leave on job sites.

I upgraded my 25 yr old Craftsman contractor saw and replaced the pulleys and belt, the rail, the blade guard, and the miter gauge.

Already lots of great posts regarding the fence and riving knife.

I'd suggest also changing the arbor and probably motor bearings. My 2012 bought new Unisaw already needs the arbor bearings changed and I don't use the saw nearly as much as I'd like. Cheap Chinese bearings and cheap Chinese grease. That's what "made in USA with domestic and foreign components" means.

I bought a Vega for my 10" Grizzly.  It comes with new bars and hardware that allows it to  adapt to most saws.

I have a Paralock still on my General 350.  Really solid saw, made in canada, and about 30 years old now.
Paralock is probably long out of business.  I would bet you could get a Biessemeyer fence and rails to fit that old saw, as long as its a true cabinet saw.

The saw was made well before there was much though about safety - no riving knife, no provisions for dust collection.
A long time ago I bought I think was a Jet splitter knife.   It was around $100 probably 20 years ago.  Not much to it, but it was worth it.  Not as close  to the blade as a riving knife, but better than nothing.   Especially when the board wants to pinch in because it was kiln dried improperly.  It will tilt with the kniife as its mounted on the trunion.   It also has a set of spring loaded pawls, to help prevent kickback.  Its always on there when I rip.

And I had to make my own motor cover so the dust collection work work better, and drill a port down in the bottom.  It works ok, but my dust collector is pretty anemic.

That's the first time I've heard of this one and although it looks as if it's built like a tank, you're at almost $400 with no rails.  By the time you also purchase rails, you are very near the price of an Incra.

A Shop Fox classic is $448 complete with rails, and the Aluma-classic is $366.

I'm on the fence about a fence  I initially planned to get an Incra, but after redesigning my saw station to include a router top, the Incra no longer fits my needs.  I'm now looking for a Biesemeyer style fence.  Simple and effective.

I would personally first try to find repair parts and see if you can get the original fence working.  It may be all you need, and you'd save a few hundred bucks.  You can always upgrade it later if you decide that's still the route to go.

Sometimes craigslist can be your friend for parts.

I had an old craftsman 100 I bought for $75.  Was going to use it but it sat for 2 years.  I was driving home from a job one day and side of the road someone had a free craftsman 3hp table saw. I grabbed it and sold the old craftsman for $100