Will I have any problems if I mount a scope directly to my 34 or do I need to buy an aftermarket mount?

Should be a normal set up, one piece mount and scope, unless you have a barrel droop problem.

Not sure what you mean by mounting directly on the 34 or aftermarket mount. If you bought a combo (i.e. it came with rings and scope), by all means mount them. Probably need to cut a shim from the plastic packaging for the rings and place it between the rear ring and the scope to compensate for the rifle's droop.

If you didn't buy a combo, I would recommend aftermarket rings (I think in this case aftermarket would be anything but RWS rings. I like Leapers one piece mounts, but two piece will work on a 34 due to mild recoil and are half the price). Get them with a build in stop for placing in one of the RWS stop holes. RWS uses shallow holes, so what I do is use blue locktite on the ring mounting bolts, align the stop screw so it is down, but not all the way down, tighten the ring mounting bolts so the rings are positioned, but still slide forward and back, slide the rings toward the rear until the stop screw stops them, and then tighten down the ring mounting bolts (real tight, but not so tight they are in danger of breaking) and then tighten down the stop screw. This will preposition the stop screw so their is no play for the more severe recoil (there is a secondary recoil in the other direction).

What I meant was can I mount a scope directly to the dovetail that come on the rifle?

"What I meant was can I mount a scope directly to the dovetail that come on the rifle?"

YUP!, but you use 11 mm rings with a stop pin to do that, right!

Wouldn't use those stopholes; they're usually too shallow on Diana's unfortunately..
It'll damage yr rail..

My solution for my 52 has been to use a Beeman one-piece adjustable mount. It clamps on the rail securely enough that it has never moved. But the pin goes in the stop hole for 'insurance'.