Seriously?....
....
....<shakes head>
....Seriously?
I know each and every one of us have come across a mob scene at our local DVD outlet as angry throngs shout in unison "WE WANT RITZ! WE WANT RITZ!" I now know why they looked at me strangely when I suggested they should try the local grocery store and not the F.Y.E.
Here's a simple lesson in DVD Economics for you Luke (and you too, false). In order for whomever owns the rights to the "all important" canons of the Ritz Brothers and Clark and McCullough (whom I had never even heard of until just now) there would have to be a demand for them. And I'm not talking about a lone loon who states his wish very unconvincingly with a meager sentence on a Three Stooges message board. As convincing as your argument is it is not enough.
You see gentlemen, manufacturing these things costs money: not just to print and press the DVDs mind you but other things like artwork, advertising and so on. So despite your obviously earnest and heartfelt plea for a Ritz Brothers retrospective ("Now we need a Ritz Brothers DVD Set from FOX and Universal." I feel your angst in all 47 letters and the period my brother!) I'm afraid it's all going to fall on Deaf ears. Now since I am fluent in American Sign Language I could accompany to the offices of 20th Century Fox and Universal but they would just sign to me and I would interpret for you what I already know: that there would have to be a lot more than one person who wants a fuckin' Ritz Brothers DVD set. In order for them to go through the trouble of making sets there would have to be hundreds of thousands of passionate, loquacious people such as yourself who also yearn for the Ritz Brothers. Sadly, the demand does not warrant supply.
Your best bet would to wait for the respective studios to offer such material for those "pick and choose your own DVD-R" deals they have on the web. I warn you though that can get mighty expensive.