The only UK Frank Zappa singles on this label were released in 1971. The same year, they stopped using the black sleeve and started using the brown sleeve. According to 45-Sleeves, the brown should be the correct one for the tan UA label.
The label of the UK What Will This Evening Bring Me This Morning/Daddy, Daddy, Daddy says “A Product Of Liberty-United Artists Records Ltd.”, same as on the brown sleeve. The black sleeve says “A Product Of Liberty/UA Records Ltd” This strengthens the theory that the UK UA Zappa singles should have the brown sleeve.
I have seen the UK What Will This Evening Bring Me This Morning/Daddy, Daddy, Daddy singles presented with both sleeves. This may very well be collectors that put it in a sleeve they find appropriate. It could also be that the single was sent out with both sleeves, since the pressing plants often used remaining stock before the new ones when there was a sleeve change.
