You are correct with regards to the 1979 Down To Earth album cover but the way Rainbow is written above was retained on the 1979 Since You Been Gone & 1980 All Night Long 45rpm single picture bags plus it was written that way on the front of the 1980 Castle Donington Monsters of Rock band compilation vinyl album and from memory the Rainbow Rising stage backdrop was still used during the Difficult To Cure tour era of 1981.