Hi
I think that the snail was a product of the 'Wedgwood' labelled King's Lynn glassworks (1969 - 1986). It merged with Waterford then, and was sold to Caithness 2 years later, whereupon it continued to produce horrid twee little animal paperweights (you may sense that I have no feel for them.....). These various cheap animal weights swamped some outlet shop shelves at £3.99 upwards until the King's Lynn factory closed, maybe when the owners realised that they could not compete with similar items from China.
Alan