I can offer the following works on double basses:
Any repairs, renovations, sound improvements & optimizations for best handling.
Dressing the fingerboard with careful attention to even concavity over the whole length as well as cross curvature adapted to the bridge. If really necessary new fingerboard with new top nut.
Set position markers onto the fingerboard if desired.
Reshaping of the neck.
Rework the bridge or if desired or really necessary make a new one.
Mount bridge wheels, preferably the Moser patent mechanics MPM, in existing bridge or new one.
Set the soundpost, if necessary replace it.
Adjustable soundpost 'Anima-Nova'
'Klangzauberstab' from Diastrad Geigenbau.
Wooden endpin for improved sound, different woods to choose from.
Replace suspension wire or rope of the tailpiece by highly flexible 2.5mm-rope made of stainless steel or on request set a synthetic one.