It depends on how long you have been out of jail. There is a deadline (not sure of the date) that if you took your exam after a certain date, all you need is seatime to upgrade.
Sounds like you will have to get the inland, and then go work coastwise on deck to get seatime on either ‘coastwise’ or ‘oceans’ to upgrade to NC or oceans. But, I believe any upgrade to either NC or oceans will require you to take the whole exam again. You can do the ‘limited crossover’ exam once you have a 2nd to get 1600 ton master. But you will have to either take a celestial class or do the exam at the REC. The seatime you will need to get NC or oceans will need to be ON a coastwise or ocean tug or OSV though.
You DON’T need to do the apprentice thing, since your license is better than a MOTV license. Once you get a 1600 all you need is a completed TOAR and evidence of 30 days aboard a UTV. And your TOAR must be signed by a Designated Examiner (DE.)
Actually, I think your license is already equal to a 500 ton master, so you could switch over to tugs, with just the TOAR and 30 days (provided you CAN complete a TOAR, and be judged competent by the DE in 30 days.)
How long ago, and was your time on harbor tugs as DH?