Some of the show reports now include a section for photos of the many steam miniatures that are a growing section at Steam Rallies. These working steam engines vary from a compact 3" scale (1/4 size) up the 9" scale (3/4 full size) models.
The larger models are being marketed by several builders as complete ready to rally engines at price a lot cheaper than doing up an old derelict engine (if you can find one) and a lot more transportable.