both specials use arthurian themes. the telltale signs that it's the filmation special is the production code (GGWB) and the appearance of pepe le pew (who does not appear in the chuck jones special). i often see drawings from this special turn up. sometimes they are not identified and are simply sold as generic "looney tunes" drawings

filmation was working off the latest of the pre-63 shutdown models for most of the characters. daffy, porky and sam all have that early 60s look, and there's a background in the special with framed photos of daffy lined up in a row, all faces from the 60s chuck jones model sheet
S. C. MacPeter
A print from the rare SING AND BE HAPPY series  Dave Fleischer did for Universal during the period Lantz had signed with UA was on ebay earlier this month. Happy to say I won it and will give some thoughts when it arrives