Matchbox was formed originally as a small scale company- thus the name. It was said you could put them inside a real matchbox, supposedly. Not being familiar with matchboxes, I don't know if that's true or just a figure of speach. I don't know when they left small scale, but it was in the 60s. I only have one of the originals, but sometime in the 1990s, I don't remember when, they did some reissues (or possibly new toolings) in the small scale, with the box. I have several of those.
The majority of the album, however, are composed of 1990's "World's Smallest Matchbox", which are smaller than Micro Machines, or even Racing Champions' 1/144th line, but larger than the Micro Machines Insiders.