The only way to see what it is truly worth is to run it as a no-reserve auction and let people bid on it. Otherwise it's worth $650, if it sells.

Okay, I know that wasn't the best answer. When these types of items have come up in the past, they vary wildly in price. From what I recall, they tend to go for $150-$300 range.
That being said, you have a really nice display kit there. I'm sure they are exceptionally rare in that condition.