this is the original release, not the more recent ones. dimensions should be the same, but i cant say for certain due to not owning them.
length measurements are from coupler facing to coupler facing.
thomas: 70mm long, around 30mm tall and 20mm wide.
annie/clarabel: 65mm long, 30mm tall and 20mm wide.
percy: 65mm long, 30mm tall and 20mm wide.
mail car: 90mm long, 30mm tall and 20mm wide.
james: 80mm long (without tender). 30mm tall and 20mm wide.
james tender: 40mm long.
express coach: 150mm long, 30mm tall and 20mm wide.
henry: 162mm long, 30mm tall and 20mm wide.
open freight trucks/scruffey: 55mm long, 20mm tall and 20mm wide. 25mm tall with load of stones or stones.
closed frieght truck: 55mm long, 30mm tall and 20mm wide.
fuel tanker: 55mm long, 30mm tall and 20mm wide.