Field Mower needs new blades. Weld OR Replace??

My thread of my First ever TIG welds shows pictures of a field mower that my dad bought new. It is 45 years old and the blades are worn probably 1-2 inches shorter than new. I think that they will be way to spendy to buy. so i can either weld new ends in these or make up new ones. either way i have no idea what material to use other than plain cold or hot rolled will wear out at a crazy rate. the end segmants are about 2-1/2 inches wide and 3/8 thick by a foot long. Any ideas? By the way, I made it!!!!:DI officially am over 60 posts!!!:D:P:rolleyes:YAAAAY! But still i need to know what kind of steel to use. Thanks in advance.