'Other' Constructional and Allied Systems Info & Downloads
Science Club Construction Set
The Build It Construction Sets have parts to similar to Eitech Construction and are classified as a Polylong(1) type sets. Not sure where these sets have come from, although they were almost certainly made in China. They were sold in 'The Works' stores in 2020.
Info from the Metal Constructional Systems Database for POLYLONG 
2003 to in production in 2018 and continuing
25 (see comment *1)
4.2 (see comment *2)
Bolts: pan (crosshead)
Steel with a Bright Zinc plated finish
6.5(see comment *3)
Various Sets (see separate list) from Polylong & other makers. Most parts as CONSTRUCTION  but some others. *1 Mod.1 & finer for Motor/Gear Unit.. *2 Square holes in some RCEE sets, see TRONICO [a]. *3 6.1 & 7.4 also reported.
Below there are manuals/leaflets which can be downloaded by clicking on the appropriate image.
© 2010-2020 Timothy Edwards