Just ordered the part from JL off of Amazon. Mine has a metal front, with the old rubber part seemingly attached by glue to that metal piece. The new part I ordered appears to be made entirely of rubber/plastic including what is metal on my existing failed one. Do I need to try to separate that metal part from the plastic, or is the new piece an entire assembly where my existing is a 2 part glued together assembly.

For what its worth, from some research best I can gather the gun is a 1979 or 1980.