Yes, David, ships like these were made at Pilkington's. I remember seeing them when we went on a school visit. I was less than 10 years old and on my first-ever visit to a glassworks. The visitor centre had some of these in display cabinets and they made a lasting impression on me.
I recently asked Pilkington's about these and was told they were friggers, and there are many of them in their collection. Joanna Hayward, their Collections and Access Manager, replied to my query and said they are not on permanent display but periodic exhibitions of them are held. They did one about 12 months ago. The friggers are not just of ships, she said, but include items such as a glass Blackpool Tower!