1964 NMM DDO???? 1 1

[Mustacheman]

I found another coin that may or may be DDO but it could just also be Strike Doubling. 
 

side question does F.S stand for First Strike?

[Mustacheman]

[Greenstang]

FS stands for Full Steps.  
I see no sign of a Doubled Die, maybe a bit of Machine Doubling and/or Die Deterioration.

[RWB]

In 1966 the initials FS were added to recognize the designer, Felix Schlag.

[powermad5000]

I see severe die erosion doubling on this nickel. This looks like a very late stage set of dies as the sloped like look is not even producing an image of doubling anymore but rather you can see how much metal was allowed to flow out of the recesses of the die to make the letters and numbers look even bigger than normal. Look especially at the bottoms of the R and T in the 4th photo. Enough metal was allowed to flow out that the severe sloping of the lettering is basically touching at the bottoms of those letters. I could only imagine if those dies were left in service any longer, they would have developed cracks.

And, the FS you were referring to in this case is for Full Steps which NGC recognizes either 5 FS or 6 FS. What this means is on the center set of steps, each step must be full and complete all the way across end to end. A hit across the steps usually will negate a nickel getting an FS designation. Also, wear across the steps will usually make the steps flat and blend into each other which will also negate the FS designation.

Edited March 24 by powermad5000

[Sandon]

   I agree that this worn 1964 Jefferson nickel does not exhibit evidence of having been struck from a doubled die and that the thickened lettering with ghostly outlines is likely due to die deterioration, a form of "worthless doubling." Coins struck from doubled dies generally exhibit crisp, clear doubling, with both images on about the same level and "notching" between the images.  

     You may find the following resources helpful:

     Double Dies vs. Machine Doubling | NGC (ngccoin.com)

     https://www.doubleddie.com/144801.html and links therein on mechanical doubling (a.k.a. strike or machine doubling), die deterioration doubling, and abrasion doubling.