is there a page detailing which version of each Sonar is the most recent and how to obtain patches to get to that state?
 
eg X3 needs base files and then X3e without intermediate patches
X1 needs base files then X1c followed by X1d
8.5 needs base files from DVD (or 8.5 download files installed on top of 8.3) followed by 8.51, 8.52, 8.53
etc etc
 
i'm missing something obvious no doubt but would like to get complete versions downloaded of everything  paid for

Hi. I didn't have 8.5, or X1.
But you can get X3 (and perhaps X1) from your account.
I've just Googled for updates.
All the best.

I believe the OP is correct. Updates for those versions are in the knowledge base. Those versions on DVD and in user accounts are not patched and need updates from the knowledge base for their latest releases.