I have this nice Unertl 10X scope that has a few features that stand out from any other Unertl scope that I have.
Are any of you familiar of these features shown in the photos?
Thanks for any information/history that any of you can share.

Photos/Questions

Photo #1:  Scope measures 21 1/4" long including sunshade which is 1", serial number is 32103
Photo #2:  The rear elevation and windage scope ring has a quite a different layout for calibration, rear scope ring base is also marked on the front base portion Pat. 2208913, the back of the ring base is marked J Unertl.
Photo #3:  Distance markings are numeric only less any yardage - any thoughts on the relationship of the numbers to distance?
Photo #4:  Another photo of the front of the scope and distance markings. There are three screws around the circumference of the scope between the front locking ring and numeric markings.  When loosened along with the front locking ring a slot is evident, look between the 0 and head of slotted screw above it and the slot shows up in the threaded portion.

I did attempt to zero this scope on a nice little Ballard 22 that I have intended to use at our local Schuetzen matches and 200 yards.   
With help, we set up a target at 25 yards to begin looking for those small holes, image was very clear and sharp (had not moved the calibrated head yet) we found the windage and impact so moved to 50 yards to begin elevation evaluation, clarity of the target was lessened but bullet impact was found again. Next we moved the target out to 100 yards, at this point the target image was fuzzy and no matter where I positioned the calibrated head I was unable to find a clear image of the target so testing stopped.
Mentioning this testing I am wondering if the scope needs servicing?
I have seen in another thread members suggestions on repair services.
Hopefully some of you are still reading this long query and some have definitive answers/thoughts.
Thanks for any help.

Thanks I just opened the rings up for the photo to show this feature of this scope.

As far as I know they all have that. The lens piece with the screw must move when you change graduations, the locking ring will do that also.

I have an early unertl similar to this. For longer yardage the lens mount ring
which is between the two knurled adjustment nuts must be moved forward.
My scopes adjustment solution are a bit stiff to move so my method when increasing the yardage adjustment is to move the front knowledge ring further than necessary and then slide the lens mount ring forward until I have a clear target and reticle. At this point I move the rear ring forward unti it touches the lens ring. Last I tighten the front lock ring against the lens ring. 
Hope this is useful.

On the number to distance question.

Read the objective Lens graduation’s like it’s a micrometer. Record the settings at typical distances that are correct for your eye. Log the settings in a notebook. The best target scopes, Unertl, Weaver T, Lyman STS and others all have micrometer graduations 

One size fits all Parallax Yardage graduations on scopes are rarely accurate. 

Boats