B Stock Or Grey Goods, How to Tell?

I'm curious, I bought an item off ebay and had problems with the seller making delivery etc. Well, I finally got item but I don't trust the seller and wanted to know if there is anyway I can tell by serial # or physically if the item is B stock or grey goods. I really don't know what the official definition of those terms mean even.Thanks!
What did you buy (mfr/model)? New? Used? Demo? There are various ways to tell if an item is B stock, but there's no cut and dry answer.
i cannot tell you anything about b stock. however, "grey" goods are items manufactured in the u.s. specifically for export and sale in foreign markets. sometimes price anomolies present opportunities for foreign purchasers to make money by buying abroad and re-selling here. you can sometimes identify a grey market item by its voltage set-up (220v instead of 110v), by its model number (it may be a mx43a rather than an mx43) or by cautionary language on its packaging (e.g., "for sale in [eurpoe] only" or "this item is not required to be serviced by a dealer outside of [the u.k.]"). the danger in buying grey market goods is that local dealers/service centers may be unwilling to service the item. if can get a serial number before you buy, you can always try contacting the manuf. to see if they can identify whether an item was manufactured for foreign export or not. i hope this is helpful.
To answer your question about "B stock", that usually refers to equipment that has been refurbished by the manufacturer. I don't believe serial numbers would be recorded during this process. Since most things sold on ebay are already used, that makes it even harder. To add to the previous post, generally the equipment's shipping box will be marked "refurbished", "RTV" (return to vendor), or something similar. If it was not in the original box, it's pretty hard to tell. You might check date codes of parts to see if one doesn't match the rest, or look for solder flux to indicate a repair. My experience with refurbished equipment has been pretty positive; if it failed, at least the infant mortality parts have been replaced!