Aeroplane Constructor Set
HCS Volume 6 has a good view of the No 2 Aero Outfit. The Outfits are stitched with the fine blue Aero String, available from Arthur Clapp. The string has to be fine - as can seen from the stitching holes in the cards are much smaller than those in the Meccano Outfit stitching cards. Here is an example of a French Set.
Photograph courtesy of Edmundo Veiga.