Rarest TrackMaster Trains

The rarity of an engine isn't just based on the quantity produced, but also on the accessibility of the product.

You can easily tell when a seller is selling the blushing Thomas as it's easily identifiable, but the international talking engines are almost impossible to determine since they look identical to their English counterparts and it would be difficult to determine what language they actually speak from just looking at the listing.

Also, quick question: what do you think is a sensible guess for the number of Latvian engines in existence? (The country's population is just under 2 million)