I'm pretty sure that's not the Lion of Sodor, which as you imply has never been depicted with a shield, and is gold. You may have to cast your net wider (I've drawn a blank so far).
Can you make out what's on the lower half of the shield, below the three fleurs-de-lys and the chevron-ish middle band?
Can you make out what's on the lower half of the shield, below the three fleurs-de-lys and the chevron-ish middle band?
![[-]](https://www.blueplastictracks.org/images/collapse.png)