Interesting. I thought all the Prestige GR models used alnico magnets.
Nope, in the last few modern series Tannoys, alnico models are distinguished by the pretty gold/orange colored horn (the strangely named pepperpot), with an empty/open throat until it reaches the back "pepper" holes drilled through to the compression chamber. The tulip waveguides are visually distinguished by their inner concentric circles, and always use ceramic magnets.
The good news for tulip driver owners is that replacement drivers cost a LOT less 😅 FYI I bought spare Canterbury GR drivers to the tune of $7K. The Glenair 10" tulips were like $600.