@colimanut,
When I had an ancient refrigerator for over 15 yrs...(yours is 24 yrs is at the end of life), I tried the same thing...buying new seals for the Doors and a new thermostat but it lasted only a few weeks more...compressor quit completely.
Even when working right ancient appliances may waste a lot of electricity and boost your monthly bills. The new ones, due to newer tech, are far better with sipping electricity.
Parts like gaskets, new thermostat and the like will be hard to find. Search around the internet on the links that Butterfly provided and you'll see what is possible to. then there's replacing parts yourself. Unless your really hands, don't bother. More than that, a service call will typically be between $50-125 not including the part you buy. Fergeddaboudit!
FFWIW, here's the link Whirlpool site to explain how to read the tag for the model number properly. if fter you've gone there, it come up with nothing, you may be relegated to getting generic parts, assuming you know what is bad *(which you don't).
http://www.partselect.com/Model-Number-Locator+9+repair.htm
In ancient refrigerators, without the proper maintenance, such as dusting off the cooling coils, cleaning the seals of any dirt/debris...and
some sort of service calls (maybe once every other yr). will lead to deterioration. You've gotten almost 2 lifetimes out of the refrigerator. Say bu-bye!
That being said, often times the problem areas can be: bad thermostat, the gaskets faulty (letting in warm air),... and potentially leaking cooling and/or failing leaking compressor.