Hey! I called the twin thing first (even made a nice pic) LOL. Crazy, and probably not true, but hey I will play the who is Cumby lottery. Cumby and Quinto have the same body type and Cumby dies his hair darker for the role, so it just seemed he was closely connected with Spock. Maybe Amanda had twins, one looked Vulcan and one looked human (entirely possible). The human twin was secretly given away and assumed the name John Harrison. As far as the accent goes, Spock's 'Twin' was raised by adoptive British parents (the Harrison's) . Anyways, wild theory, but that's all part of the fun!