I don't expect that a lot of people will have use of this exactly as-is, at least you likely want to use a more modern controller. I have therefore attached a STEP file of the full assembly so you can modify it to your liking.

I used the spool holder from an Ultimaker 2+, an Ultimainboard 2.1, an Ulticontroller 2 (so the electronics from an Ultimaker 2), and a Sparkfun OpenScale to interface with the load cell.

The load cell is a ring-shaped model from Vetek, art.no 247W with a 50kg rating. This load cell has an 8mm hole, so I then machined custom adapters for each hotend I wanted to test.

For the E3D V6 heatsink in the pictures I just turned the groove mount down to 8mm, threaded it with M8 thread, and secured it with a nut made from a bit of alu rod with a matching thread.

The Extruder mount was made for a Bondtech QR as it was one of the strongest extruders I could get my hands on, as I was mainly testing the relative back pressure of nozzles at different flow rates. The extruder mount is a separate piece so I would be able to switch between different extruders easily.