These boxes could be of special interest for collectors, due to the interesting fact that the two boxes are different despite the same set number.
One box type is flat and with cellophane sealing, and the other with more "cubic" shape and the new type of tape-sealing. See the pictures for visual.
I have found these differences for all the boxes:
7856 7857 7858 7860 7861 7863 7864 7867The differences are both in shape, size and sealing. I have some of these sets for auction now, in pairs with close to perfect exemplars of MISB boxes.
From the date-text on the boxes (or the non-appearance of it), I assume that the oldest packs are sealed in cellophane. Maybe the reason you see this differences just on these sets, is that they were produced over a long period of many years, during the whole Lego 12V grey-area. And during this time Lego went away from the cellophane sealing. The interesting thing is that these sets show this directly.
- many many many more
Best regards
Christian