Jonathan
Yes, I saw the Jack Crosstree reference earlier in the thread which is what made me think of Dibdin's efforts. There was a Jack at the Windlass, Jack Binnacle, Jack Brace, Jack Junk, Jack Ketch, Jack Oakum, Jack Steadfast, so Jack Crosstree seems inevitable. Is there a Boney version with JC in it?

The actual Dana passage certainly puts it down as a lively work song, but it could have been a Dibdin song adapted. Some of Dibdin's choruses are imitative of the earlier shouts like 'Yeo, heave ho'

Hugill in 'Shanties and Sailor Songs' says of 'Cheer up, Sam' 'ELSEWHERE, he gives Cheer up Sam as a shanty they used.' This suggests to me that 'Elsewhere' meant not in 'Two years before the Mast' but in some of his other writing.