Air filter inlet coupler ideas

I have 2003 Mandalay 38A w a Cat 3126E pusher. It has 40000+ miles. Ive put maybe 2500 on since Ive owned it. I finally got the air cleaner out of the left rear compartment. (Nightmarish fun!). There is a plastic coupler on the inlet side that goes from 9.5" down to 6". This coupler is before the catch box that connects to the hose that runs up tge back of the coach. The coupler is mangled. I could probably duct tape the damn thing back on but would rather do this right and replace. Cat said its a motorhome manufactured item. Mandalay went out of biz years ago. Ideas??? I have a few pics but cant figure out how to post.