I looked into the cheap boosters as my original VH44 had failed. After talking to a few repair places, most said to stay away from the copies as once they failed you had to throw them away - they can't be repaired.
I ended off buying a new one from Minisport -
https://minisport.com.au/mini-moke-vh44 ... -pbr-brand. Yes it was $500, but given it's a safety related item I didn't want to take any shortcuts.
I saw this as better option compared to the $700 odd people are quoting to rebuild a 40 year old booster, or risk the dodgy knock off. I know originality is important to people, but my van is far from original so went down this path.
Related - I have an old VH44 for sale if someone wants one, could probably use a rebuild kit as I think some of the seals etc are gone.