I purchased the soundtrack of Star Trek III: The Search For Spock on vinyl on 9 June 1984.
From my 9 June diary entry: "Today I bought the original motion picture soundtrack to Star Trek III: The Search For Spock. It cost $10.49. The jacket is the best yet with some great photos from the movie. Unfortunately I won't be able to play it for some time since our stereo set is in for repairs. The strange thing is that there are two records -- one which has both sides filled with music and another separate record which has one side COMPLETELY blank and the other side has one song of less than 4 minutes in length entitled "Theme of Star Trek III". Weird!"
I provided an update on 2 July: "I've also finally listened to my ST III soundtrack which I brought with me to Lindsay since our stereo is STILL in the repair shop. It is more melodic and beautiful than the soundtrack to the second movie which had more action tracks. There was also a fair amount of re-working of ST II themes in this album, mixed in with good new material. The single, which is scratched a bit at the beginning, is a rocked-up version of Star Trek."