The Marion Evans "Blue Champagne Cha Cha" is an instrumental. I would think that Eric Jay is the kid singing "Little Drummer Boy" & that is why he is not mentioned on the Oz release.
We also had the other sides of Bullesye 1021 & 1018 as another single on Philips - Eric Jay - "Silent Night" & Marion Evans - "The Bandit".
The most popular recording is by the Harry Simeone Chorale, who hit in the US in 1958 and every year up to 1962, reaching a high of No.13 in the first year of release.
Eric Jay’s version comes from the US Bullseye label (Bullseye 1021). Eric’s only claim to fame is that on January 12, 1959 he tied with the Harry Simeone version for 20th place in the Canadian charts .
The B side comes from Bullseye 1018, which was credited to Marion Evans.
When the disc was released in Australia on the Philips label, ‘Blue Champagne (Cha-Cha)’ was credited to Marion Evans and her Orchestra. Not a mention of Eric Jay.