Does anybody know where these pickle barrels came from? Were they Lend
Lease?

No, they were exclusively used by the USAAF.

"The target for the Eighth on 4 April was the Renault plant near Paris. Three
diversions drew the German defenders away and permitted the lead 305th Bomb
Group to destroy the complex; 498 out of 500 bombs fell within the target
area."

--"JG 26; Top Guns of the Luftwaffe" p. 156 by Donald L. Caldwell

Walt