As I recall, the FORD instructions for a fully opened system, such as you are facing......requires that the accumulator be replaced, which includes the desicant.
I also agree that, if you have low/no refrigerant, that you almost certainly have a leak someplace.
You might get lucky and just need a "O" ring seal.
The most unlucky would be the evaporator coil inside the heater box inside the passenger compartment........major labor to change out.
If it is the evaporator coil, then the dye will be seen running out the water drain tube from the passenger compartment.
I had the evaporator coil develop a leak on my '96 and had it replaced.
The shop used a "sniffer" tool to try to detect leaks.....checking first around the compressor.
When they did not sense anything, they put a dye in and had me come back another day......and the dye was to be found running out the water drain tube.
For my '96......
FORD re-designed the evaporator coil and heater box which requires that the whole heater box and its contents be replaced as a whole unit......over $450 for the part, plus the labor to change out.
My shop found a after market replacement that was to the original design for $128.
Wisconsin does not permit the refrigerant to be sold to the public.....which complicates the DIY approach to A/C repair.
In my case, I was more than happy to have someone with the experience and equipment to competently diagnose and repair the problem.