hereīs the background to the Ferdinand story. Porsche made 90 chassisī so I believe this to be the correct number, so far.
Porsche had much influence in the German industry and the Henschel prototype was finished just three days before it was to be demonstrated to Hitler on 20th April 1942. In fact the Henschel tank had not been even driven under its own power! The prototypes had to be driven 11km to the test site from railroad. When unloaded from trains, the Porsche prototype already sank into the soft ground under its great weight. Both of the vehicles broke down several times during the drive.
When tested the Porsche proved to be faster, but it was a lot poorer to maneuver. The Henschels version almost catched fire during the test drive, but it was not noticed. It was probably the most maneuverable tank at the time, and it was simpler to manufacture. So Henschel won the contract. Porsche was also ordered in case of delays with the Henschel model. Porsche made 90 chassis which were later converted to the Ferdinand/Elephant tank destroyers.
http://www.hut.fi/~tlindgre/konig/history/data.htm
On achtung panzer they said there were also six PZ III`s functioning as ammunition carriers if I understood it right. Could these be counted wrong, as Porsche didnīt get the deal so they didnīt make more of these tanks. And tanks in repair might as well be counted " again"?? SOme thoughts flying...