Davros' prototype

Whilst still using a dilapidated wheelchair, Technician Davros constructed a prototype machine for his project to create intelligent warrior robots with the mutated brains from badly wounded Kaled soldiers.

Roughly pear-shaped, it was constructed of heavily studded metal with a wavering eyestalk at the crown. Unarmed, it was made to obey Davros' commands but its the voice control circuits were still faulty, resulting in a delayed response. The prototype was presented to General Ravon and Security Commander Nyder, whom rejected it and ordered Davros to create a more impressive machine lest his project be terminated. Noting that Ravon displayed fear when the prototype advanced on him, Davros constructed a hi-tech life-support chair for himself before completing the "finished version" of his machine, which he designated Dalek One. (PROSE: Davros Genesis)

According to the Dalek Combat Training Manual, Davros abandoned two prototype Travel Machines in favor of the Mark III Travel Machine. (PROSE: Dalek Combat Training Manual) By one account, his own hi-tech chair was the Mark I Travel Machine followed by multiple prototype Daleks, the Mark II Travel Machines which would come to be used by the Skaro City Daleks. (PROSE: The History of the Daleks)