I would just like to point out some errors in the descriptions. I realize that you are not responsible for these labels or descriptions, but other readers on the thread might get the wrong idea that they are accurate if I do not say anything. I mean no offense, and I find your posts in this thread interesting, but I just want to clear up any possible confusion.
1. There was no "Prince Hahansu" in Asante ("Coomassie" or Kumasi, was the capital of Asante). In fact, "Hahansu" was a Dahomean prince. He was from Dahomey and lived in the capital of Dahomey. Therefore, this depiction of a house of idols of his could not be a depiction of somewhere in Asante to begin with, from the simple fact that he was not an Asante citizen, but in fact a Dahomean prince that lived in Dahomey's capital.
"Burton does not mention meeting any vidaho during his 1863-1864 visit, though Maurice Glele claims that Prince Ahanhanzo had been named Glele's vidaho even before the 1858 death of his grandfather, Gezo. By 1871, however, Ahanhanzo was in place and actively playing the role of king-to-be: Skertchly met and much admired the young prince, noting that "A more generous, hospitable, intelligent young fellow I never met. . .and I felt more at home with Hahansu than I had done since leaving England." As vidaho, Ahanhanzo enjoyed a central place in court politics and ceremony. However, within fewer than five years of Skertchly's visit he had died under mysterious circumstances. . ." - Edna Bay, Wives of the Leopard: Gender, Politics, and Culture in the Kingdom of Dahomey, p. 274
And there is also the plain fact that the idols depicted there are much more reminiscent of vodun than they are of the material culture of Akan religious practices.
2. There was nothing like a "mgenda" as a "principal gate" of the palace that existed at Kumasi. I don't think "mgenda" is necessarily a made up word, but it sounds much more like a Fon (Dahomean) word than a Twi (Akan) word.
Then there is the other problem that the building style depicted does not match any Asante depictions or descriptions, and instead seems to be similar to certain depictions of some mid-19th century Dahomean buildings found in Frederick Forbes' 1851 account of Dahomey.
3. The images seem most likely to have been drawn from imagination by someone who was not directly there (Kumasi), or they are an amalgam of other drawings made by different people who actually had been to Dahomey, not Asante. I tried looking for the source of the images and all that I was able to trace them to were British newspapers and general purpose British encyclopedias from the 19th century, which were not actually written or drawn by people who had been to either Dahomey or Asante.
However, one source that I came across actually claims that the images were supposedly made by J. A. Skertchly. But it is clear that Skertchly did not claim to have visited Kumasi or anywhere else in Asante, and certainly not at the time that these images were created. In fact, in the preface to his book on Dahomey he makes it clear that when he was on the Gold Coast, he never went to Asante.
Yet the writer (in Harper's Bazaar) in the source linked above, for some reason proceeds to label them as being of "Coomassie" (Kumasi, Asante) anyway and insists on Skertchly as a source despite the impossibility of him being a source on Asante.
Either the creator of the images assumed that the two places (Dahomey and Asante) would have looked the same (which is far from the case) or that person believed that the two places were somehow connected. I think the author's confusion and their citation of Skertchly may have arisen from the fact that the Dahomeans had actually named one of the regiments in their army the "Ashanti regiment". Skertchly mentions in his book (pages 370-373) on Dahomey that a regiment in the Dahomean army had that name, but these were still Dahomeans, not Asante soldiers. The person who read Skertchly's account and saw where Skertchly mentions "Ashanti soldiers" could have confused those as being actual Asante soldiers (rather than Dahomean soldiers who belonged to a Dahomean regiment named after Asante) and gained the mistaken impression that Skertchly visited Asante. But when one actually reads Skertchly's book in context it is hard to see how any confusion could arise about the fact that Skertchly was still in Dahomey and was describing Dahomean soldiers.
So the original source seems to be missing and the images seem to be from imagination (perhaps also based on written descriptions of mid-19th century Dahomey) or a result of a mixture of aspects of different images of Dahomey along with the creator's imagination.
4. Also, if you read the comment on this page, at the bottom, you can see that someone else has also identified one of the images as being (an attempt at) a depiction of a place in Dahomey, and not actually of somewhere in Kumasi.
Thank you for the correction and the further clarification Your tolerance as well, especially given the characters this forum tends to attract. I honestly appreciate your input in African related threads on here.