When I was researching the DePatie-Freleng theatricals few years back there were two titles that drove me crazy: Nippon Tuck (1973) and Killarney Blarney (1974), both part of the Blue Racer series of shorts. At the time these two were left out of the list of BR cartoons and I didn't even know these two existed until Jerry Beck gave me his list (before that I found a German copy of Killarney; at the time BR was very hard to find and thus I used any little material I could get my hands on)
By the time Blue Racer came out Hawley Pratt pretty much stopped directing shorts. He did a couple of Hoot Kloot and Dogfather shorts later but he eventually retired from the animation business. Art Davis stuck around for a while and did a handful of BR shorts that were actually pretty good (Camera Bug, Blue Racer Blues, and Support Your Local Serpent are my favorites in the series). Gerry Chiniquy's entries were either shrug-worthy or just not good, but I felt he got one out of the park: The Boa Friend.
Then eventually Art Davis left the studio to Hanna-Barbera. While there were occasional guest directors such as Roy Morita, Art Leonardi, Bob McKimson, and Sid Marcus, the only real director left at this point was Chiniquy and he really went downhill as the seventies went by.
I think this BR short is the the point where the downhill sets in. While the animation in DFE shorts were always low-budget and limited, they were at least livelier looking than the works of their competitors such as Filmation, Hanna-Barbera, or even Walter Lantz, mainly due to the presence of Pratt. However by this point the animation had downgraded to the point that it looks no different than the Saturday Morning schlock that was on contemporary TV.
The animation of the Racer is scrappier-looking than usual. The one part that gets to me is where he tells the leprechauns "Well what do I look like? I'm a snake!". The Racer, for some reason, has a very brushy eye-brow in this scene. After he says that line, however, the brushy eyebrow suddenly disappears and returns back to his usual floating eyebrow seen in the rest of the series.
And just to add to the seventies-ness of this short, they got Paul Winchell to guest voice the two leprechauns.