That is a k3/k4 seat. Rare and hard to find, decent recovers are out there now, weren't a year years back, to me I dont think it worth it.
Yes I even did my research and discovered that.I believe 72 (k1) is all by its self, 73-76 the same, 77 and 78 the same, 79 one year only, 80-82 the same, as far as seats go.