Welcome aboard, and this is a long shot, and new as stated above,maybe source it out, I have 2 sources for "new/used/something that will fit-one is a place that specializes in bumpers I've been to, in Portland OR, Genuine Bumpers Inc, they did well for a 75 Dart front, I didn't want bumper guards so they didn't charge me for them, and front and rear for the wifes Sebring they were really reasonable price wise-they have a free delivery so they must ship-maybe, but go here and look if your still looking
Genuine Bumpers — Auto Bumper Covers and then we have a wrecking yard near here I could live at. The amount of parts they have is one thing, the collection of knowledge is another. First time I saw it I figured this was where God has stored all his oldie but goodies, MOPARS, and thats what they have,
https://www.wildcatmopars.com/, and I hope that don't step on anyone's(vendors) toes, they are just local resources that are exceptional compared to others I've dealt with, and if I did, "sorry" in advance!
Nice lookin Duster too. Good luck finding it. Re-chroming might be the best way to go if it's a good solid one, places out there too, verses trying to match one thats "close enough", as an afterthought.