I found the original version just a tad to sweet and upped the gin to 1 1/2 part. Mote closely resembles a wet martini, and more to my liking. Even so, a very nice combination, especially for those not into gin martinis.
Used Mr black for coffe liqueur and homemade chocolate and coffee bitters. Probably quite a bit dryer than the above version; but I generally find drinks with Kahlua far too sweet.
However, with a bit of maraschino jar syrup too taste it is truly a very palatable cocktail.