Huh? That's a pretty cryptic thread title.
But to answer your concern directly, I'm surprised that you didn't know that you can back-save AE 10.5:
http://help.adobe.com/en_US/aftereffects/cs/using/WS3878526689cb91655866c11...
Look for the section, "Save and back up projects in After Effects CS5.5"
Now, none of the new features in 10.5 will show up, but I'll guess you weren't expecting miracles.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA