Sorry for the late reply.
I jailbroke with the Kindle 5-4 jailbreak. This worked correctly and ***JAILBREAK*** appeared.
I then used Update_python_0.10.N_install_pw2.bin following the instructions [HOME] -> [MENU] > Settings -> [MENU] > Update Your Kindle
The first time I did this I got error 06. I applied the jailbreak again as I wasn't sure if the error was from that and then ran Python again which this time gave no error.
Finally I put Update_linkss_0.17.N_install_pw2.bin into my root directory and did [HOME] -> [MENU] > Settings -> [MENU] > Update Your Kindle. Once this was done I put a blank file named cover in the linkss folder and did [HOME] -> [MENU] > Settings -> [MENU] > Restart
I tried a couple of books, but both just gave the standard screen savers. The book covers do show fine on the home screen though.