Live recording from Vancouver, BC. Recorded March 21 1970. Pb is considered to be the very first Zeppelin bootleg to be released.
Pb, Pure Blues, packaged in a plain brown cardboard cover with the legend Pb (the chemical symbol for lead) hand-stamped on the front cover with a rubber stamp, the record makes no mention of Led Zeppelin anywhere on it. Except for the stamped image the cover was completely blank, and the label on the record-which incidentally is an exceptionally good pressing, especially for a bootleg-is bright yellow and bears only the words P.B. Live [side l & side II] Recorded Live - Pure Blues.
Link to white cover variation: https://www.discogs.com/release/33571083-Led-Zeppelin-Pb-Live-Pure-Blues