License holder no longer around, update needed

[CZ Eddie]

Hi, I just wanted to confirm that we are out of luck?
Currently on vBulletin 4.2.0 and wanting to update to 4.2.5.
But the person with the vBulletin site password/license passed away some years ago and we no longer have access to that license information.

1) So we are out of luck, there is no way to download the 4.2.5 update, is that correct?

2) If so, we will be forced to purchase a vBulletin 5 license as 4 is no longer available?

3) And if that happens, how good are our chances of a rookie admin updating our site from 4.2.0 to 5.x without losing any data/members/threads/pics/etc?

Thanks,
-Eddie