If you're an experienced blacksmith with the knowledge of how to form and temper springs (the closest modern steel equivalent is in the 1060-1085 series), have availability to wrought iron for the jaws and other parts (mild steel will work but it's not PC), etc. not that hard at all and patterns are available, but if you do not have that type experience or the proper materials as Black Hand noted it would probably be less problematic and cheaper to purchase one from several smiths that do that type work.