Geo,

One place to start (perhaps you already have) may be to take that great bibliography you have been developing, and pick out the non-shanty bits. Then divide it into songs versus instrumental music. The instrumental music references will be far fewer, so probably more manageable. The songs part is tough because sailors might sing ANY song that was around then, though through LOADS of work (maybe more than you'd like), you could determine which ones tended to be most associated with sailing ship men. In any case, you may have to decide on some more limiting criteria for this.

Gibb