A bit of progress with the DIY String Butler like rotating string trees.

I went to Hobbyco in Sydney's City center on the way home from work the other day, basically to see if I could find two lengths of Brass tubing that one could fit with precision, within the other.
After measuring my Gibson's, I found that to emulate the strings trees used in the String Butler, they would need to be at a height of 10mm, sans base plate used with the String Butler, as these string trees would be direct mounted.

The idea is to have a inner diameter Brass tube cut to 10mm height, screwed down to the headstock, but before it is, it has a outer diameter Brass tube surround it, cut to 9mm height, so the inner works as a Axle, and the outer rotates around it, the strings rest against these outer tubes.
A simple Brass wood screw, with a head large enough to hold both tubes in place will do the job.

Well I found what I needed very easily.
Hobbyco- stock numbers are with #
https://hobbyco.com.au/
Both lengths of Brass tubing came in 36" lengths [which is enough to make at least 20 sets of 4 string trees ]
Stock #1148 7/32 x .014 Brass tube -use this as the inner axle- cost was AUS $9.95
Stock #1149 1/4 x .014 Brass tube - use this as the outer casing which the string will rest against - cost was AU $11.50