Seems your query has been answered, but for anyone who may acquire a bell there are a few clues to look for when trying to establish whether it belonged to a launch or cargo vessel. A launch bell will usually be in pristine condition. A cargo ships bell inside the bellmouth will have all kinds of marks on it either from a chipping hammer, marlin spike, or BP hammer, this is because the striker (clapper) had been removed for the sea passage and someone had forgotten to shackle it back on when coming into an anchorage, so the nearest tool was used to sound the bell on the inside (never on the outside) when sounding the chain in or out or aweigh. Sometimes the clapper was removed in port, as some stevedores lifted any thing that wasn't secured down.
Even small coasters of 1000 grt upwards the bell would weigh in the region of 10 kgs and have a bellmouth diameter of 30/33 cms.
