I'm not sure of the differences between 8mm and super 8 but surely you can just convert an 8mm pocket viewer to accept super 8?
If the film sprocket holes are different then you could change the sprocket for a super 8 spec one.
If the film is different width then you could change the 8mm spool for a super 8 spool.
As i said i don't know the difference but with a pocket viewer in hand i'm sure it wouldn't be difficult to see how it could be adapted because they look pretty simple inside, judging by that Ebay picture i linked to.