Nice fly Craigie. Had a lot of joy with my own version, and also with a 'Dabbled' Soldier Palmer Muddler.
The pic.. make sure when you take the shot that the only thing in the frame is the fly and the background that you want - in this case, the card, and not any sky etc. The sky in this instance has adversely affected your exposure.
If you just frame the fly and a small amount of the background (trying to get the shot as close to the final crop as possible) you will usually end up with something like this, or better....