"Writtens done" makes it much easier.
Could you not spend your last few months in the States working in Florida instead of San Diego?
Work at one of the schools that does JAA CPL training and you could build your last few hours and get the CPL ride out of the way at the same time.
You will probably find the CPL 'check ride' much easier in the USA (with all your USA experience) than you will if you try to do it back in the U.K.