Sorry Mike, but I probably know about as much about it as you, apart from...
The film size quoted is a bit smaller than 5 x 4 itself at 99 mm × 62 mm and I believe the finished print is ejected, which then develops outside the back, with nothing to peel off / apart.
I went to the Fuji site to check out the price of the required film, but this gave me 3 pages and 22 options of various film sizes and colour / b/w combinations, so I'm a little confused at the moment, as to which film is required. From the google ads though, Argos seem to be the cheapest supplier of the Instax film, at about £15 for 20 shots / pictures.
I will be interested though, to read the first few reviews, probably from known photographic people, to basically promote it.
Terry S
PS Dave has just got in there in front of me, and I am now aware what film it takes. Thanks Dave.