I hope you like a challenge.
I have the new 34C (Classic) and it differs from previous Diana 34s. The scope rail is longer and the UTG scope mount (DN034) made for the Diana 34, does not fit the new rail. The rail is 1 inch longer and the UTG mount sits too far forward and unless your scope has a longer than normal eye relief the scope will be too far forward.
The new scope rail besides be an inch longer also has two additional stop-pin holes and these holes go all the way through the rail as opposed to the shallow holes found on previous rails. I doubt that these new through and through holes will tear out.
PA sent me UTG Leapers Accushot to try and it doesnít work really well either. In order to mount it and so the stop-pin will fit in the stop-pin hole the screw at the rear of the rail with the large head must be removed. There really isnít any problem in removing this screw as it doesnít hold the rail to the rifle. I can only assume that this screw is intended as a scope stop, but the threaded shaft is rather small and people have reported that it is easily sheared off. The Accushot mount doesnít have any compensation built in and on my 34C the POI is about 4-5 inches low at 30 yards. That is a lot of elevation to dial into a scope and I would need to shim the rear ring.
I removed the step (ledge) from the DN034 mount and it now fits as it should and the pin-stop and pin-stop-hole line up and I can position the scope for proper eye relief. The problem Iím having is that the compensation that is built into this mount is too much and the POI is about 5 inches high. This mount will require that I shim the front ring.
The POI is with the scope knobs zeroed, done by rotating the knob lock-to-lock and counting clicks and then setting the knob midway. If I get some time today Iím going to shim the DN034 and see how that works. I like the Hawks rings that I bought to go with the DN035 better than the rings on the one piece Accushot. I may, after the holidays, investigate either a set of adjustable rings or a one piece mount like the B-Square (http://www.pyramydair.com/s/a/B_Square_17501_Interlock_Adjustable_AA_1_Pc_Mount_w_1_Rings_13mm_Dovetail_Fits_BSA_Rifles/253
Until some company creates a mount for the new 34C, or Umarex starts importing the new mount from Diana, I think adjustable rings are the way to go. Iíd really like to find some adjustable quick release rings so the scope could easily be removed so the iron sights could be used. However I donít want to spend more on a scope mounting system than what I paid for the rifle.