Kevin,
All of the R4 race reports have been placed in...
The R4 Forum
For a number of years now.
At the top of that forum is an archive of all six of the previous R4 race reports as well.
The other IRRA Permier race reports (for The Sano, RetroPalooza, Fall Brawl, etc.) are located in similar subforums at the top of the IRRA Retro Racing forum.
Are you just missing where these are located, or are you wanting something else?
As for the All Star Invitational race report, the only info I saw on that race was posted to Facebook. Good luck tracking that info down now.