Tried to post this on the other one but it got locked.
Hopefully this one won't be.
Explain the plaque please. Not interested in your black mate.
The key words here are 'available' and 'estimated'.
'Using all available wartime records from the various camps it has been estimated that between 400,000 and 500,000 people died in the entire German concentration camp system (from all causes).'
These figures are based on what was available and then someone 'estimated' how many died.
It does not take account of the number of records that were destroyed when the nazis realised they were going to lose the war. These documents may have run into several hundred thousand records. Spend an afternoon destroying sheets of A4 paper in a garden brazier and see how many you can burn. Now multiply that by several hundred people in an afternoon and 'guess' how many pages would be burnt. Now multiply this number of afternoons by several months and then 'guess' how many records could be destroyed. It is not a hard task to 'literally' wipe all traces of someone off the face of the earth if you have the determination.
The Holocaust happened Joe, face it, millions of people were murdered and all traces of them wiped out by a ruthless zealot with control over weak minded individuals who looked on him as their saviour.
Regardless of the 'Freedom of Information Act' there will be things that you and I, or even our Great, Great, Great grandchildren will never see.
And Google is not infallible.