Here's a thought on the use of Assaye and Punjaub. Delving into 'what-if' territory, what if they had sailed into Havana? Pull a
'SMS Goeben and SMS Breslau' some 53 years early? The Union could not ignore them that close to US shores in a well equipped deep-water port. Even if the Spanish didn't welcome them with open arms, and I believe the dry dock there belonged to the RN, the USN would have to react. A long distance blockade? Up close to Havana? That isn't going to make the Spanish happy...and draw forces off of the Confederate Coast Blockade.
2409
Just a thought,
USS ALASKA