The Tanzer 31 was one of the last models built by Tanzer, they commissioned the design from C&C but I'd reckon very few were built. I'm sure you've seen this:
TANZER 31 sailboat specifications and details on sailboatdata.com
Anyhow, one of the last C&C designs with the traditional springy sheerline, she's a handsome boat, typical fin/spade underbody and reasonable stats, 40% B/D ratio. Tanzer was known to build a pretty good boat, and this one is arguably the best looking Tanzer ever produced. I'd give it a go if it looks clean and passes survey.