Confusing Release Order
The first six models were released as 'Zybots Advanced Changeable Robots' on black cards with photo images; photos of the prototypes were used.
These six were then re-released on red and yellow cards with illustrated character images as 'Zybots Changeable Robots' along with an additional four models bringing the total to ten.
A further eighteen (numbered 11 to 28) figures (many recolours of previous models) were issued as 'Zybots NEW Convertible Robots' also on red and yellow cards.
This is where it gets messy
Previewed in the 1985 REMCO retailer catalogue and presumably released that year are the Zybots II, Zybots III and Zybots IV series; mostly prototypes used for the photos.
Zybots II was released with numbering also starting at 11 and ending at 13.
Zybots III figures don't have model numbers and Zybots IV numbering followed on from Zybots II adding 14 to 16.
Using all available information the most likely release order was: Advanced Changeable Robots, Changeable Robots, then Zybots II, Zybots III, Zybots IV at the same time overlapping the Zybots NEW Changeable Robots were release.
Then there's the Blue Cards
Again, previewed in the 1986 REMCO retailer catalogue are the 'Zybots NEW Super Changeable Robots'.
These included all of the Zybots IV models as well as REV-2 from Zybots II. These cards did not show a model / figure number on the bottom right corner as was traditional for all Zybots blister cards. The NEW Changeable Robots assortment was featured on the rear of the cards with the model numbering of 11 to 28 but without the figure names seen on the red cards. NEW Changeable Robots and a number of items presumed never to have been released were shown in the same 1986 catalogue.
It's unclear where they fit into the release order. As they feature in a catalogue at the very end of the Zybots run along with items thought not to have been distributed they could simply be hastily created cards to replace the incorrectly numbered Zybots IV cards and sell off extra REV-2 stock in the process.
Zybots were also released in Italy by GIG, however it's currently unknown whether more than the first six black cardbacked figures, the Multiforce set and Splash Robo renamed to 'Robo Splash 1' was sold.
Delavennat distributed the Multiforce set in France but it's not known whether individual figures were also sold.
If you have any supportable information or research leads please get in contact!
Stamping
Zybots Advanced Changeable Robots / Changeable Robots have either 'Macau' or 'China' stamps, some with minor paint variations linked to location of manufacture.
Zybots II are stamped either China or Hong Kong.
Zybots III and IV are stamped China.
Zybots NEW Changeable Robots are almost all stamped 'Macau' on small, inlaid rectangles with the exceptions being Lil' Yellow and Rock Buster models where the under canopy stamp was not updated.
Bibots are stamped China
It's likely REMCO planned to manufacture in both Macau and China then depending on location glue in the rectangle Macau stamp to cover the China mould stamp as needed. As no examples of empty stamp cavity 'China' models have been discovered this may not have occurred.
Another possibility is in 1986 China began negotiations with Portugal to transfer rule of Macau to China and Macau based manufacturers may have preempted this by building in easily changeable stamps vs. reworking figure moulds. With Zybots being manufactured into 1986 and Bibots 1992 potentially all of the figures were made in the same Macau factory stamped either Macau or China.