Sorry can't help you there; I never had to take the written exams for my FISO Licence as I had a validated Aeroodrome Control rating on my ATCO licence when I applied.
If you ask on Flyer Forums, there's a guy called AlanM on there used to run FISO courses at one time; maybe he could help. You could try a PM on this forum but he hasn't been on here for quite a while.