Missing unit picture

[Lowlander]

Thanks, that did the trick, and a lot easier than the method I first tried.

This brings up a related question: how do I remove the 'has boats' feature from the Russian engineer units that are not labeled as pontoon engineers?

You don't as these are assault boats for ferrying troops across rivers and canals, check rule book page 48. Plus check on full water hexes same section.
Units being ferried must be " on foot " or horse, and MUST be in travel mode.

The engineers with " has boats " cannot build a pontoon bridge.