Hi Xavier Wells,
i dont want to be too long :
to listen: Red Mitchell after 1968 disc, end others that others tell before me.
to study the fifth tuning you needennis Masuzzo's book: "playng the double bass tuned in fifths CGDA" it is/has the simple mode to pass from 4th to 5 th tuning.
Next level is represent by Joel Quarrington's books the first develope the quarringon's technique the secon is like Franz Simandl/Ray Brown intervals studies.
I write from Italy, and here the simple/cheapest things to do to acheive the low C note, is change your tuning, because the extension are taylored on your bass not all liuther has skill to add it on your bass in Italy, cheapest because you need : a set of strings, a new upper nut and eventully a new bridge, tuning in fifths are fre of vibrations that can be appear if you have an extension !
Lastly try to type on google: doublebass tuned in fifths and begin to read, there is lot of things !
If You like to pass on my YouTube channel is dedicated to the 5ths tuning!
https://www.youtube.com/@tuneyourdoublebassinfifths/featured
Matteo
Matteo,
Thank you for the suggestions and tips. I'll make sure to do some more digging into those method books!
Best,
Xavier Wells