The calls that I mentioned should provide the data you need. The field "QuantitySold" is in there. Isn't that what you're seeking? There's also total quantity. A little arithmetic and you can also see how many haven't yet sold.
This is not answer: Hello. I have a question. Why am I not receiving the same response with the "FindingAPI.findcompleteditems call" that I get with the "ShoppingAPI.GetSingleItem call"? And I see that ebay and terapeak uses the same "FindingAPI.findcompleteditems call" to get their results. I sold some items but my username does not show up in the "findcompleteditems " results. But they do show up in the "GetSingleItem" results. It was a single listing with multiple available. I was thinking maybe it was the SOAP Version that I was using which is "1.13.0".Am I not able to retrieve single listing with multiple available data with the "FindingAPI.findcompleteditems call" ?