Old Adjustable Machine Heads / Tuners

[Adey]

I've bought an old 70's ish Precision Bass copy. It has the old machine heads that have the adjustable sleeve on them so you can alter the tightness of rotation.

 

The proper tool to tighten it would be a litle C spanner / hook and pin spanner. I can't find anyone that does teeny weeny ones for this. I have currently just tightened with a pair if pliers and rubber protection to the spindle, but it would be nice to find a better / proper tool for it (or I might make one)

 

Any ideas???