Well what i normally do is have the item history of the unusual up. Open up 2 of each seller's and buyer's backpack. Then adjust the dates to when the unusual is still in the seller's backpack and when the unusual is not anymore(This doesn't work all the time. It is variable. If you are lucky and it is clearly shown, what i like to do next is sort the items by time. (The idea is because when the unusual is traded, the time of the items in the same trade should be similar. Therefore, the sweets etc should be next to each other). However, keep in mind that this is not always accurate. It is just a rough estimation of any sweets involved. Hope this helps.