[GaoMuscle Longhorn]

Going to go out on a limb here and guess that the Dozer Ressha is actually a Snowplow.

Because a train with a bulldozer blade doesn't work; it'd tear up its own tracks!

Other guesses for the other lost resshas:

Hyper: A prototype Shinkansen that goes REALLY fast as the base. Presumably this one, when attached to ToQOh, gives it ludicrous speed.
Mixer: Fairly obvious; this one is rail maintenance that dumps the gravel onto the tracks. The "mixer" part comes from its finisher being spinning up that gravel into a funnel and spraying it at the enemy
Safari: I'm hoping a mistranslation and it's actually a Circus train. If not, then it's definitely some sort of animal carrier

Wants for lost trains:
Chemical Ressha: a chemical transport train that is Indigo or Navy, and can entirely replace Blue Ressha. Final attack involves igniting the chemicals and blazing the enemy with them
Armored Ressha: A Beige armored train, splits into two components that attach to the arms for lots of firepower
Cannon Ressha: A Safety Green railway gun that clips onto the shoulder of ToQOh while the carriage clips onto the legs. Can't move AND fire this beast!
Metro Ressha: A White streetcar and allows stealth somehow

And Chemical would get a two-parter based on Unstoppable.