Cracking good yarn. There had to be a way to get those two into the Victorian Holmes and Watson and other than just doing it, being a pure "Rathbone did that bit better but he..." comparison, there had to be a twist. I enjoyed the twist.

Mind Palace has been a fascination with writers for years. Hannibal Lecter was the first character I came across who used it in that sense.

On balance? I reckon they should stick to their present day concept for future ones. It's their niche.