Readers Who Need Readers: Tom Glazer

A reader has sent me this request:

"As a kid my sister and I had many of Tom Glazer's records ("Music Ones and Twos", "Let's Sing Finger Plays" and a few others) but I have been unable to find any CDs by Tom Glazer for my twin daughters. I know he is dead now. But who owns the rights to his old recordings and are they available?"
I really only knew Tom Glazer as the performer on three of the Singing Science records from the late 1950's/early 1960's. (If you are a They Might Be Giants fan, you must immediately click on the link above.)

I've ordered a couple of the disks off eBay, and got something which was, well, it didn't look like it was a fully authorized version. (Whether it did or did not pass intellectual property requirements I will leave to other, more qualified kids' music writers to determine.)

This guy may be able to help the reader, but how about you... any thoughts?

(Bonus link: Time magazine's recommendations for the best in kids' music... in 1960.)