This was authenticated on the CAS website as "Carl Reiner" but I've had a few Carl autographs in my possession and this sure doesn't appear to be his handwriting.
The Kevin is definitely a personalization but the autograph seems a bit different than the Carl's I've seen. The R looks more like Rob Reiner's R. It could be a very old Carl Reiner and rushed in person but it still seems far off from Carl's I've seen.
I will do a little more looking into his in person, older styles and thank you guys for the replies!