According to the Museum, the memoir "relates to the key areas of maritime disasters and stowaways, and is particularly interesting as a contrast to the Naval Court’s findings of the incident on the St Cuthbert. The detail relating to the problems with the lifeboats also forms an interesting parallel with the Titanic."
This inspired me to seek out the findings of the Naval Court - which I'd somehow neglected to do before. They are here, and do indeed give a very different account of some of the significant details, generally in the direction of exonerating the senior officers at the expense of the junior ones, and still more so of the largely foreign crew.
My one disappointment is that the tweedy curators who I'd hoped would be travelling to Bristol to collect the book are too busy organizing an exhibition on Nelson, so I've got to post it. Even without the Royal Mail being privatized, that is somehow less romantic. But altogether this is very pleasing.