Sivus the Virus: Blocking out continuation 3

Since I have run into a new problem and haven't been able to get any ideas on how to mirror the other half of the left tentacle I've come up with another idea which would be to snap that tentacle in the middle again, then choose a set amount of faces in the area I want the left tentacle to go to, extrude and delete, then all that's left is to carry on grafting.

(That's plan B, Plan A is for some helpful advice but I think plan B is the only way to do it now)