Vinyl Releases
The bootleg comes with both LPs in a regular sleeve, whereas original has a gatefold double sleeve with one LP in every fold, hence the features newspaper articles are printed on the inner LP sleeves rather than inside the gatefold. There is a small error in the Pyramid Blaster logo (the right speaker is filled black), and on its back cover there is a huge KLF logo. Apparently, the original back cover later changed, though, so the logo is just a possible hint.
While the original Shag Times had the cat# JAMS LP 3 on its spine, the bootleg got issued as 'JAMS DLP1'. The runout groove is labeled 'JAMSD LP 3 A' etc. and is, like on most bootlegs, produced by machine, while the original had all text written by hand (and only said 'JAMS LP...'). The record labels themselves have been retyped and got a black ring on their border, while the original didn't have one.
Furthermore, the font on the cover is not 100% accurate. Letters like "S" and "G" are too rounded on the top, and the "J" doesn't do a full curl.
CD Releases
A French 15-track CD appeared in 2012. Since the original pressings only include 14 tracks it's pretty easy to tell them apart.