Hi Mark,
TomTom as well as we offered an upgrade path imideately after the release of TTN5.
We do no longer offer that path and AFAIK TomTom does also no longer of the Navigator Update 3 to 5.
With TTNCF5 you need the SDK 5.0 for licensing purposes.
TTNCF3_5 includes the SDK things you need - so what you need in addition to TTNCF5 and TTNCF3_5 is the SDK 5.0.
We do not offer non commercial license in any form as well as TomTom does not for the SDK.
By the way - you can find the TomTom SDK at http://www.tomtom.com/pro
Regards
Manfred