I couldn't find the ArcKit Link Component 8.01 in the files published officially at Sketchup Warehouse (almost everything is there except this piece). So I endeavored to reverse engineer it and publish it.

This link component is available in all physical kits ; it is also available for sale separately at : https://www.arckit.com/products/8-01-link-x48

You can use 3D modeling and 3D printing to create custom components to integrate with the stock ArcKit ones.

ArcKit makes wonderful architecture model building kits for education , hobbyists and professionals: https://www.arckit.com/
ArcKit at Sketchup warehouse : https://3dwarehouse.sketchup.com/search/models?q=arckit