We must have both collected our Drulovs at a similar time - I got my Condor from City Air Weapons Solihull in the Nov period. Sooooooo much fun. I love the fact it's both fast AND capable.
I fitted a Rowan scope rail (designed for a Umarex 586) to mine this morning by drilling & tapping a pair of M3x0.5 holes in the top cover. Fitted a compact 4x28 SMK mildot scope. Not a proper pistol scope, but good for starters, and I had it handy. The result was 15mm groups at 20m outdoors with 6x RWS Gecos.
On mine I find that most things feed will if I keep the pre-load screw set flush with the front of the cover, but some can still function well with it wound in a bit further, such as the Gecos with it set level with the back of the striker when cocked. I get 6x in comfortably by trimming about 1mm off the rubber buffer inside the bolt/probe thingy. I did try removing it altogether but found that when the waiting pellets were sent backwards by the co2 pressure, they would a) be deformed by the hard landing of the probe without the buffer, then b) be sent back into batter a bit too hard often resulting in double-fires.
One of the things on my list is a co2 chamber extension to allow more space for the co2 to absorb heat and also to minimise the pressure drop when firing (since a proportionally smaller amount of the gaseous co2 would be consumed). I might do this by a) using a spacer to allow 1x co2 cap to be pierced as per usual, or b) make up a device to allow 2x caps to be pieced at once to provide more co2 to start with.
If the extension were made of alloy with fins for increase surface area too... hmmm.
Or just make up a new cap with a Q/D fitting to run HPA at 1,100 psi via a remote line to a 4,500 psi bottle and reg.
So much potential for these things!