Not to have reliability would be one of the issues to me. A real good cleanout of the fuel tank and supply lines would be on my worklist. You do not want a lot of sludge or whatever is in the system from your description.

If engine is presently running well things overall may not be too bad and I would deffer the diesel purge. You have a perhaps a more pressing issue.

What the inside of the fuel tank and tank strainer are like is something I would want to know. The rational is quite simple. Avoidance of a roadside breakedown is far cheaper and far less disruptive than eliminating a potential cause. The fuel lines can be blown out and solvent cleaned I think as well.

If and when you feel it is time to change the injectors with known good ones I would not loosen up all the junk in the injection pump and push it through known good injectors. Push the junk through your current ones.

Diesel purge is like a tune up type of chemical. Soaking the injection pump with a solvent in place may be more effective. If there is a lot of blowby present from the oil filler cap or engine has any other issues that may indicvate the rings are not free. Adding miracle mystery oil to the cylinders and soaking them can help. Reading the archives gives lots of ideals and methods people have used.

Hunter is absolutly right. Some components in the fuel system are precision by nature and can be damaged by bad fuel and contaminates. . The amount of damage if any can be estimated later.