As you must already know the era of shanty recording largely done by relatively sophisticated people was one where the printing of unexpurgated shanties was not the done thing. The only thing we have that tells us that some of the shanties were crude is witness accounts of the time and even then these are in short supply. There are several mentions in the shanty threads here that Stan knew quite a lot but even he in the 50s and 60s, when his knowledge was being revealed, was very careful about where and when he would reveal them. There are some claims that his versions do survive in private hands but so far these haven't surfaced. If Stan was in the Merchant Navy or even the RN he can't have failed to have heard and even sung what we now mostly call bawdy ballads/rugby songs which have always been part of the staple repertoire of HM Forces and thrived during both world wars. How much overlap there was between the forces songs and those sung during the 19th century aboard merchant ships will probably never be known, but one imagines there must have been some.