Here's a link to some excerpts from what's being billed as the last in-depth interview of Larry Gelbart.
Note that in it Larry confirms that he never was a writer on Your Show of Shows. Sid Caesar had a succession of different TV series and Gelbart worked on the one Sid did after Your Show of Shows. It was called Caesar's Hour…but folks have a way of lumping all the Caesar programs together under the general umbrella of Your Show of Shows and often say that Larry (and Woody Allen and Sheldon Keller and Gary Belkin and a couple of others) worked on that series. Not so.
Also, here's a speech that Larry prepared and apparently never delivered anywhere.