Unknown application without cap. The bag does hold water but while emptying it, it was discovered the canvas has a 1”tear below the right side mounting grommet. It may be fixable and useful. Price is $7 plus shipping and is located in Arkansas.
This part is very nice and here is a link to it from this sight. It is reduced to $95 plus the shipping and located in Illinois.
For Sale - ‘64 Chrysler front end trim
For Sale - ‘70 300 Rear Bumper
This link should show the pictures and information on this bumper which is $135 plus the shipping and located in Illinois.