MV Eastern Princess, Great Yarmouth, 1961.

This vessel has an entry in the records of the National Maritime Museum:

EASTERN PRINCESS (Br) 50.6 1942 Pleasure launch at Great Yarmouth, harbour and local cruises. ex. ML347 Southern Coastcraft Ltd.

They have several photographs dating from 1949 onwards, one showing that she had a funnel at some point in her life.

The Eastern Princess was something of an attraction during her time at Yarmouth, old postcards sometimes turn up on Ebay.