Thanks to everyone for your responses, all were very helpful. We checked in at Jost without any problems. We had assembled all the documents that we thought would be necessary to establish that our boat was no longer a charter boat. As it turned out, the customs official did not ask any questions, look at any documents, or have any concerns about our boat as an ex-charter vessel. We checked in at a total cost of $107 US. It was as smooth as silk.