Thanks for the advice Mark, I also used the heat gun to remove the glue however the problem I have is there is a very thin film of glue left.  The wood is now smooth however it won't sand properly due to the residual glue. 

As this is my first cab, I don't know if this is normal or whether I need to do more to get back to wood with no glue.  I'm going to try some metho & white spirit tomorrow.