This is probably one of the most awesome Mr. Belvedere related video I've seen on You Tube so far. It's an almost 10-minute interview with the entire cast of the show before the start of the 6th and final season.
I think Bob Uecker is hilarious here. He makes jokes but he never smiles and that makes it more hilarious. Christopher Hewett also reveals how he got the part of Mr. Belvedere over the others who auditioned for the role.
Thanks to "brockpierce1984" or Robert from the UK for uploading it. I don't know how long it will be up there, but I hope You Tube allows it to stay indefinitely. I hope Robert does to.
In any case, if you have Firefox, you can always download the FLV file with a video downloader plug in.