The bike is not mine its slippa'sHi Jerry
The last one was a bit unexpected.Home-made job.
It's exactly what the late, great Sheldon Brown wrote about doing when he was younger - he made several tandems out of standard bikes by welding strategically.
I've been looking seriously at making either a tandem or cargobike frame myself, for two main reasons:
1. Carrying capacity
2. The cost of a bought one
3. Being able to fit a mid-mount motor and almost unlimited battery space.
4. The Spanish Inquisition