Picked up from Flying Tiger for around 3 quid - a set of small wood carving tools.
Quite why someone decided that these were a useful addition to the slightly eclectic stock, I'm not sure. They work reasonably well on obechi however. I needed to gouge out some channels for the ramps up to e level crossing and it was easier with the larger half-round tool than anything else to hand.
The smaller chisel is probably worth the cost on its own for those who need to clean solder out from joints on kits.