With your CIMA qualification you should be able to get a practising certificate from CIMA especially if you are only looking to do bookkeeping.
Also, with your CIMA qualification you would be able to gain full membership of the AAT from whom you should also be able to get a practising certificate.
For information, if you have a practising certificate with AAT, CIMA would not require you to have one with them (and vice versa).
The AAT qualification focuses heavily on bookkeeping up to Level Three so you could refresh your knowledge by reviewing the bookkeeping elements of their syllabus. I would recommend Osborne Books for textbooks.
In regards to marketing your skills:
Employers are much more familiar with CIMA and AAT compared to ICB.
Smaller clients in your own private practice would be less discerning about qualifications but marketing yourself as a Chartered Management Accountant would probably have the most impact.
Hope that helps.