Dom, the scale you picked is perfect for the 9" Dahlgren Shell Gun and the painting, the historical photo and the modern pics we have taken around the United States which can be seen below, prove that the muzzle flair you turned on your Micro-Dahlgren much more closely resembles the 9" than the 11".
Tracy and Mike
Very little muzzle flair can be seen in this famous painting depicting the battle off the coast of France in 1864 in which the Federal Steam Frigate, Kearsarge sent the Notorious Confederate commerce raider, CSS Alabama to the bottom with a few well placed shells from her Pivot Gun, an 11 Inch Dahlgren Shell Gun. Photo of painting from the Naval Historical Center.
The historical photo here from LOC.com is of an 11" Dahlgren Shell Gun mounted in Federal Fort Putnam on the northern end of Morris Island in 1863 or 1864 where it could shell CSA held, Fort Sumter in Charleston Harbor, SC. Not much muzzle flair here, either. Dom, this is the shifting pivot carriage that all 11" Dahlgren's were mounted on in Federal service. Just like the 200 Pdr. Parrott Naval Rifles, they were too heavy for the Marsilly type tail dragger carriages, wood or metal.
In June of 2007 Mike and I found this excellent 11" Dahlgren at a small park in Exeter, New Hampshire. We studied it thoroughly and noticed that it had much less of a muzzle flair than a 9" Dahlgren that we saw later in Hartford, Connecticut.
This 9" Dahlgren we found on the Campus of Trinity College in Hartford, CT is one of the best cared for naval guns we have ever found. With perfect paint, clear markings and a super carriage, recently replaced, it is one of two on that campus. My uncle, a Coast Guard Captain, went here for two years before he transferred to the Naval Academy in 1938.
Mike and I found this 9" Dahlgren Shell Gun across the bay from the Mare Island Naval Shipyard in Vallejo, California. We think Dom's beautiful Micro-Dahlgrens look very much like the 9" in this picture, larger muzzle flair and all. A 24 Pdr. naval gun for a Sloop of War resides there as well.