How would I be able to tell the difference on a wrench so as to note wether it had the jappaning finish or some sort of paint. Thanks for any input
Cmon Rusty, its you and me

lol....Japanning is soluable in light oil...but testing it will damage it....

Thanks for that, so just to clarify, any type of light oil will make it smear like tar, is that correct?

Yeah, found that out the hard way one...

As an aside, long exposure to petroleum will soften some enamels also, but generally not instantly...

Also, I don't know how you tell apart the tar/asphault based japan type finished and cured  linseed oil/carbon black that will also smear...(perhaps there is no point?)

Thanks again

What? Oil won't harm good japanning! You can soak it in oil, if you want.
     Japan is baked in an oven.  It's almost has hard as glass.
  Its way way thicker than paint, most times.

  Regular paint? You would have to lay down 99 coats to get it so thick.

I suspect the stuff that dissolves in oil, and smears off of your hands, is some kind of tar. 
  yours Scott

I kinda thought the same thing but Rustys a good man for at least trying, most people are so afraid of making a mistake ( which is bullshiz ) that they dont even bother to post what they think. I figured someone else would add to it and set us both straight. I know I have oiled many a plane thumscrew ect and never had an issue. Thanks Scott  and thanks again Rusty

Perhaps the stuff I have been dissolving is some kind of cheapo incompletly fixed finish.
I don't have any nice stanley planes to dissolve....  ; P

The few old enough to be japaned wrenches I have run across that still have any kind of finish on them seek to me like they are probably enameled, except for the ones that I have dissolved, What I have seen as a finish on a plane looks different that what I see on wrenches generally....

Crinkle-coat is something else we should talk about some time, a lot of wrenches that people think are unfinished, I suspect were crinkle coated, as that paint is awfull and flakes off a few years after you put it on, leaving a nice shiny steel finish...

What do you mean you don't have a Stanley plane Rusty?
You need one?

Yeah japanning
You lay it on, and it goes on like cold molasses.  Its ridiculously thick. 
Let dry overnight.
  I usually do 2 coats over 2 days.
Then put it in the oven at its lowest setting.   Bake 1/2 an hour and cool.
Now bump up the oven 75 or 100 degrees and bake again, an hour this time.  Let cool
Another bump, another bake.
   Keep going like this until you hit 350-375
  Once you are done, the stuff is almost as hard as glass, but tougher. Thick black and very shiny. 

Obviously you want to do a whole batch at a time, so do lots of tools to fill up the oven once you start.
It smells a little like asphalt baking, but even my wife will tolerate it.

Oh, you can lay down multi coats of decent enamel, and bake it the same way. Rustoluem etc.
  Japan only comes in, "any color you want so long as its black",  so if you want another color,  try baked paint.
Same baking procedure and you can do it along with your japanning.
It comes out terrifically harder than air dried. But it does smell more, so better send the wife to the movies. :) Cheaper than the mall. :)
     yours Scott