Based on eBay listings there seem to be 3 basic types, with some variations within each type.
Type 1 had an all-black viewfinder housing without rangefinder, and I don't think it had an extinction meter, as the later models did. There was a 4-speed version (1/25, 1/50, 1/100, 1/125, B, T) and an 8-speed (1, 1/2, 1/5, 1/10, 1/25, 1/50, 1/100, 1/150, B).
Type 2 has uncoupled rangefinder and extinction meter and the viewfinder housing is chrome with a leatherette top. There are least 3 shutter variants: (1/25, 1/50, 1/100, 1/125, B, T) and (1, 1/2, 1/5, 1/10, 1/25, 1/50, 1/100, 1/150, B) and (1, 1/2, 1/5, 1/10, 1/25, 1/50, 1/100, 1/300, B)
Both the Type 1 and 2 had "Agifold" in a 'double-hexagon' logo on the viewfinder housing and the front was opened by moving the housing sideways. They had a 90mm f4.5 Agilux Anastigmat lens.
Type 3 has a fixed all-chrome viewfinder housing with uncoupled RF and extinction meter. "Agifold" is written in plain text. It has a 75mm f4.5 lens. There seem to be 2 versions, one with knob rewind and shutter speeds 1, 1/2, 1/5, 1/10, 1/25, 1/50, 1/100, 1/200, 1/300, B, and one with lever rewind and shutter speeds 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/350, B.
Very likely there may be other variants I've never spotted!
I don't yet own an Agifold, but I'm currently reassembling a couple of Agimatics, which are a neat little 35mm uncoupled rangefinder camera. You can see that the designer must have sat down with a blank sheet of paper when starting on these. They owe very little to any other camera I have met, and seem to be well thought out and decently made. When these cameras were made, the company was based at Purley Way, Croydon. Pleased to see they are still in business!