Here's an idea

I woke up in the middle of the night last night thinking about how I might create a pioneer figure for my Bavarian infantry.

RSM do a couple of figures in their waistcoats with empty hands as part of their artillery sets. I'm thinking, perhaps a grenadier head-swap, a greenstuff apron, a scratchbuilt axe, a loose musket on a sling and a painstakingly built-up coat and I might be there.

The bare head could be transferred to an Officer or NCO who might then be persuaded to hold his hat in his hand.

I'll let you know how I go with that.

I'd like to go further too with my Grenadier officers and actually arm one with a fuisil and a belly-pouch (did the French call them "gargoussiers"?). The Austrian Officer advancing with his "spanish reed" in hand looks a promising subject.