The Rock'n'Rollercoaster was designed, built, tested and themed by WED (Walter Elias Disney) Enterprises, AKA the Disney Imagineers. Vekoma just provided the manufactured/fabricated pieces, this is the same with Space Mountain:Mission 2 in the Disneyland Resort in Paris.
Did you know that Disneyland Paris does not own either of it's Rock'n'Rollercoaster or Space Mountain:Mission 2?
These rides are owned by WED Enterprises and are rented to Disneyland Paris. The Rock'n'Rollercoaster in Florida was also owned by WED until it was signed over to Walt Disney World until late June of '99.
To back this up and to answer the original question that started this topic, please follow this link, scroll down to the bottom and read under "Facts and Figures"
sm.dlpfan.org/history/construction/index.html