This is very interesting! I made an account, though I hate having to make so many accounts. Now I find I can only search for the surname, not the name of a farm.. also, that there is precious little information about these farms. No (OSF) number or diagram.
I was trying to find Josua Joubert Gideons son, at the Zeekoegat farm along the Hexriver. I find many other farms, but not this one..
And I found for "Ary Jacques Joubert" the farm "houdden bek gelegen over de Zoute Rivier agter de NVallei berg in't NVallei".
That sounds like the famous Houd den Bek of the later revolt.. except for the description with Zoute Rivier and 'NVallei'??
Anyway, intriguing stuff!