Tannoy - Ferrofluid for 1" tweeters

Hi there!
Anybode got reliable info about how to replace Ferrofluid in 1" Tannoy Titanium Tweeters (6189 0063) from 2004 (199X-20XX?? i8, V8, etc.) ? Like: how much to apply and where to buy?

There seems to be different viscosity and magnetic propierties..

Thanks!
MH
 
hey,
I just researched a bit again and it seems the original Tannoy stuff like this:

Tannoy Ferrofluid Syringe 7900 0604 150uL - Speaker Exchange

has the following properties:
150 uL (.15 ml)
921 APG
Gauss 165
Viscosity 200

Did not find 921 APG but 821 APG again from ferrotec:
https://ferrofluid.ferrotec.com/products/ferrofluid-audio/apg-800-series/apg-821/

But the question remains how to get this stuff here in Germany and how to apply the right amount..

I mean there are so many tweeters with this problem so I don´t really get why there is not more activity in this respect..