– source : https://thearmoredpatrol.com/2017/11/13/9-21-british-td-armor-changes/
(Thanks for Ogopogo from WotLabs)
AT 2:

- Cupola is same
- big parts of frontal armor are thinner.
AT 8

- frontal weakspots removed
- The weakest parts on itβs front are 152 mm thick.
AT 7

Similar treatment as the AT 8.
AT 15

- Mantlet no longer has weakspot behind it
- UFP is now 139.7 mm. Cupolas are thicker as well.
Tortoise
- Entire front became stronger.
- The roof is now 57.2 mm thick
