Softdrink
Professional
It's hard to tell from the photos, but if the plastic topper is in two pieces (IE: if the center section separates from the two side sections), it might be possible to vacuum-form it. That would be a super inexpensive way to get it produced in a small quantity (though you'd compromise a bit on the strength of the repros compared to a milled, printed, or molded solution). It depends on the draft angle of the parts - if the corners are < 90 degrees it should be theoretically possible.