The seahorse head was a reference to when the Mafia left the head of a horse in a guy's bed as a warning, and was done by the Brotherhood as a similar warning.
The locations I found were quite big relatively speaking and quite different to each other.
Overall, this has been the best one for me, YMMV.
"They'll get my gun when they take it from my cold, dead, furry white paw." - Vote Max for a Brighter Tomorrow.