Catalog# "6499 724 10" appears on the back sleeve (top right) where the "10" is contained in a square box. 

A1 to A4, A6, B1, B5, B6: ℗ 1973.
A5, B3, B4: ℗ 1972.
B2: ℗ 1971.

Sleeve: Printed in The Netherlands
Label: Made in Holland

Also issued [url=https://www.discogs.com/release/10359990]with longer text on label rims.[/url]