You could take the carb off and dribble fuel into the intake runner and probably get it to start.
You have nothing to lose by trying to start it with the carb that's installed now but you also run the risk of damaging the engine if other precautionary steps aren't taken avoid ruining the engine.
Fuel tank, fuel lines, probably fuel pump are all likely gummed up.
Attach a fuel hose to the inlet side of the fuel pump and put the other end into a gasoline can with fresh gas. DO NOT attempt to use the 30 year old gasoline in the tank that's full of rust and who knows what?
Remove all the spark plugs and put some motor oil in each cylinder and turn the engine over by hand with a wrench on the crank snout. Remove the pushrod cover and valve cover and watch everything move while you do this. Make sure all the valves and pushrods are moving the way they should.
