Initially I reverted to 4817 and "connecting" did indeed display the pre-live
fake XOnlineDash.xbe as you described (and consequently didn't download anything). I then replaced it with 4920 and it attempts to download ... without success ... I think my network setup's incompatible and will try changing that when I can eh.

Edit (outcome):
Changed the network setup and received 5960 but nothing more, alas. My tests proved to be somewhat futile, as I don't have Live! Consequently, I could only gain access to it via the dash.
Learned that my version of Fever2k3 doesn't facilitate the initial connection, it just displays a message about visiting the XBL website for more info. The owner needs to have subscribed by another means, before this version of the game can use it eh.