Here is half a water pump plier turned into a drawer lock chisel.
In a tool catalogue, it says it is “indispensable for cutting small mortises in tight places.” Well, agreed. But a price of over £70 makes it a luxury item, unless you are a professional cabinetmaker. And if you are, I don’t see why you can’t cut the lock mortise before assembling the drawer. Admittedly, for that price, you get two chisels, and each has two edges, with two orientations. Also, mine is not “precision ground O-1 tool steel.”
The handle has been made from a bit of salvaged beech chair leg.