Great find.
If you want to maintain, or even increase the value. Leave it as it is...especially if it is still sealed in a plastic wrapper.
If this is not the case, then shoot the crap out of it.
When it comes to lefties, they usually are worth less than right handed bows...less demand. However, keep in mind that the limba on these bows are interchangeable left and right, so this should not effect the value of the limbs.
Just taking a stab at the value of brand new '83 limbs, I would say about $300 per set, but some individual may pay more.
I bought a brand new Custom Takedown atoud 2000 and paid $800 + shipping. I don't know what a new 2009 would go for.
I will tell you this, In my opinion, an '83 is a lot better bow than what is being sold today.
Now, before Wade jumps in and asks just what I base that on it is purley on what I think about the quality of the Bear bows back then as compared to the crap that Escalade is putting out today. Can't say I am wrong as long as I preface it with "in my opinion".