Anybody have info on The Beatles White album on white vinyl with smudges?

This vinyl is colored and has some brown and black smudges on the record. I have heard rumors that this issue had contamination problems and some were distributed while others were pulled once the problem was identified, and it has since been a collectors item. Anybody has any information on the story, the value or how many were pressed?

SEBX11841
Capitol Records purple label. Says "mastered by capitol" on trail off, released in 1978 with a high gloss cover.
Has a triangle symbol on trail off and the matrix run out is crossed out on both disc.