I have a gas can from a 1955-1959 transporter. It's green molded plastic with a black screw on cap and black screw on spout. I saved it all these years thinking it might be worth something someday. It may not even be original equipment.
Can someone reply who reads German and tell me what this means?

Reserve-Kraftstoffbehalter 51
Pruf-Nr. BAM 3.1/5791
Kautex-Werke

There is a circle like a clock numbered like a clock with 19 in the middle and an arrow pointing to the 5 on the clock. I'm assuming 1950.

Anyone? Thank You,
Gary