First off, Hearts of Steel was a What if...?/Elseworlds type of story. ("What if the TFs awakened a 120 years earlier?" basically.) And, believe it or not, there have been nearly ten TF/Joe crossovers over the years but, aside from the two Marvel ones, they're basically set in alternate continuity as well. : ) It doesn't bother me as long as it's worth reading. Honestly, some of it hasn't been.

What I forgot to mention: That locomotive Prime can be had as a transformable model kit ⚠️ ↗, but it costs a little more than it's worth in my opinion. (Upwards of two hundred bucks.)

Just because it's fun, here are a few other characters...

Shockwave ⚠️ ↗ with battle ship mode

Megatron ⚠️ ↗

⛓️‍💥[Removed] (Nice try...)

Some obscure bloke named Bumblebee ⚠️ ↗

The Insecticons ⚠️ ↗

Devastator ⚠️ ↗?

Shocking spoiler: Astrotrain appears! Even Ratchet was a train. There were ambulatory trains at the time(1867), but ⛓️‍💥[Removed] would've been much cooler. Not only a better fit for Ratchet, but...Hearts of Steel was great, my only complaint is enough with the trains already! Though trains do fit into the plot and I suppose it wasn't easy coming up with metal alt-modes for that time.