Unertl Ultra Varminter

 I recently obtained a 15X Unertl Ultra Varminter with a dehorn rear mount.  Can anyone tell me how to adjust it?  I tried turning he knurled knobs but they don't seem to want to move.  Are the hex shape protrusions caps that are removed to provide access to adjustments?  Help!  I'm desperate.

I have the enertl 15x commander. At first I thought my micrometer adjustments weren't working as it had been in storage for many years according to the man I bought it from. I learned through trial and error that the threads are so fine that movement of the scope itself is hard to detect but it was moving. Each of those knobs by the way accept a very small allen wrench to loosen the knobs to "free" spin...used for setting up the scope, sighting in and  then returning the knobs,not to reposition the scope. Zero your rifle for whatever range you want, loosen the knobs and set the scale to"O"and retighten the knobs. Now when you adjust the scope for a difference scenerio you can always retun the scope to zero which was you sighting in position. Gently re-tighten the allen screws and you're set to go. Each click is 1/4 m.o.a."Springer2" forgot to mention that the front mount is the pivot mount. In setting the optics use the ocular optic for sharpening the cross hairs only....once you've achieved that clean crisp picture then you can use the objective lens to bring the target into sharp focus and you're good to go. I'm curious about the model you have...what is the tube diameter, style of crosshairs, eye relief and does the scope have screw-in lens protective caps? Are the bases standard or Bosa style?  Don't forget to put a drop or two of light oil on the top rail the scope slides on during recoil. If you have a spring installed the scope will reposition itself automatically....if not gently pull the scope reward until it hits the stop ring. You have a super scope, equal to some of the so called high rollers and it is quite valuable in its own right as a classic.