Try Tony Murland at Needham Market in Suffolk. He normally has 3 or 4 antique ones in. I got a fully forged 10 inch one for £26, probably well over a hundred years old, made from one piece of iron bar with a proper forge welded eye. Not a piece of tube welded onto a bit of leaf spring like the modern ones often are where you depend totally on the weld for strength. Also it has a full-wedge shaped profile, not parallel with just a small grind like the modern ones. I find it enters the wood more easily (gradually) when you are starting the split....