Nothing they could easily get their hands on.
Was on the 'crazy Red Chick' when she visited scouseland back in the nineties. Before ship open to visitors all valuable and attractive items not nailed down were moved off the upper deck or secured in the interior areas which were open.
This included all the fire hoses and nozzles from the baskets. Nozzles and hose connectors were brass. On completion of SOTV the duty watch returned them to the baskets, the following day the whole process was repeated. Never did that anywhere else in the UK and it was done following recommendations from previous ships visits where the nozzles had been nicked and the connectors sliced off the hose's.
So, to answer your question Vampire, I would suspect they got away with very little