Well – solving the stock quantity issue was easy, I ran the following SQL:
WHERE `meta_key` LIKE '_wpsc_stock' AND `meta_value` <1
I tried telling the importer that I would choose to upload images in the next step. Spent 25 minutes choosing the 272 images for each product. Hit the Upload and Import button. (went away and made a sandwhich) came back and the screen had refreshed to the start of the import products screen – no products or images imported.
How can this be?