High Standard Model Identification

Can someone tell me the difference between the Supermatic Citation models 106 and 107?
I lost the slide lock spring, so I logged into Numrich to see if they had any and they do. My problem is I cannot tell which model I have based upon the markings on the gun and the part number for the spring varies depending on the model. I'm confident it's 106 or the 107. Any other clue besids the plunger release for the 5 1/2" bull barrel, silver trigger & mag release and bridge rear sight?

The slide lock spring is the same for all the High Standards 106 & 107.  Slant grips models too. 
Wolff Gunsprings:
https://www.gunsprings.com/HIGH%20STANDARD/CURRENT%20MODELS/cID1/mID28/dID139#176

I suggest you call Wolff and order the 5 pak of slide lock springs, and special order a 5 pak of trigger bar springs which are also easily lost.  Also get a couple recoil springs; standard 5.5 pound if you tend to use lighter recoil SV ammo like SK, or 6 pound if you tend to use stronger SV ammo like CCI SV.

16531

HI-STANDARD .22 AUTO, SLIDE LOCK SPRING Pak of 5

7.89

If you are not familiar with the serial number ranges and roll markings evolution, a couple ways you can tell a 106 from a 107 is the 106 have the bullet shape brass filler low on the backstrap.  The filler sometimes is visible in full brass, outline only, or covered and not easily visible. 
Also, inside, the 106 hammer is grooved for the hammer strut off center, while the 107 hammer is grooved center. 
There is a difference in the firing pin as well.  But I am not sure if that change happened at early and later model 107.  This change is seen if the roll pin for the firing pin is 1/16 (early), or 3/32 (later)

I am not sure that you have a 106 or 107. Both of those pistols are clearly marked on the right side. Well, I have never seen one that wasn't marked.

Come to think of it, I believe all 106 should be marked 106.  Models 107 were first marked 107, then just Military, then nothing beside the serial number

So mine is a later 107 model because there are no markings other than the serial number.
Thanks guys, now off to order the springs from Wolff.

The 106 is often called the golden bullet guns, because they were made using slant grip fixtures, which made the drill bit for the mainspring exit the back of the grip. The hole was filled in with brazing, and then stippled and blackened to match closley, but as they wear, you see what appears to be a gold bullet in the butt of the grip. The 107 was made using new fixtures, and thus eliminated.