I have seen Shenandoah figures converted to Victorian British. Several come with the trousers tucked into the socks, and the sack coat is close to what you need. 54mm though.
One of my favorite subjects ever. Beautiful sculpting. Does the expense pouch seem a little gigantic to anyone else? Looks like a PPSH ammo pouch. Not much of a detraction from the piece though. As it is designated "#1" I hope this means more of them and maybe a Zulu or two.