PC800 Parts Needed

I'm looking for the following parts for my 1998 Honda PC800. All of the online sources and all of the Honda dealers I've contacted say they are discontinued. Do any of you have suggestions on where I might find them?

Air Cleaner Tube, right 17257-MR5-000
Air Cleaner Tube, left 17258-MR5-000
These rubber boots connect the air cleaner to the carbs. I can find the left ($21 at motosport.com) but everywhere else says the right is not available.

Carb Insulator, left and right. I think the part number is the same for both 16211-MR5-670
These boots connect the carbs to the cylinder heads.