My congratulations to Patrick!!
Immediately after his posting suggesting the answer, I went through the Austrian books I have and the websites I have bookmarked and came up with nothing. I should say, I found the same advertisement just by Googling "Gräf & Stift Granit 32".
I then spent almost 3 hours Googling dozens of possible combinations trying to verify that Gräf & Stift actually license built the Phänomen truck. I found no evidence that Gräf & Stift had a license to manufacture this vehicle. I also tried to decipher the name and address of the dealer "Autohaus" from the advertisement but the resolution of the photo is so bad I also came up with nothing there.
I have come to the following conclusion, and I am not arguing a point here, that as Vienna was up until 1955 part of "Occupied Austria" and Vienna was surrounded by the Soviet Zone. They may well have imported some vehicles from East Germany and they may have then been sold under the name of Austrian manufacturers.
A difficulty I still have is that Wendax' photo shows some distinctive ID points that do not seem to appear on the IFA vehicles.
His shows a "square" drivers door and a cooling door on the side of the motor hood, something I do not find on the IFA variant.
Also, the unique design of the rear wheels I have not found anywhere, let alone on a Phänomen, IFA or Robur vehicle.
I hope some else can find more proof that this is in fact a license built Phänomen, not something sort of "made up" by a dealer.
Bill