I'm feeling too old to McGyver things now. I can't see what I'm doing properly anymore and there's always the problem with where I've left whatever tool that is needed for a critical part of the project.
I did genuinely buy it to produce a single tool for an older drive type for work as Im no longer steady enough to do it free-hand like I used to. The cheapest I could find the tool (and have delivered to the UK) was 500 euros each (I needed 2), by the time vat, delivery and import duty were all added they were going to cost me 6x the price of the printer.
It took me a couple of days with the calipers and I killed a few donor drives getting the measurements right, but I now have a tool I can print to do the job for just 8 pence worth of filament whenever I need one. They're obviously not as nice or refined as the brushed aluminium ones but they do the same job and they're cheap enough to be disposable.