Its a Honda part, Its called a Radiator Cowl. I bought the bike new in 2001 and put the cowl on that year. Cost new was $200.00 . Very hard to find these days.
That's good to know. Maybe I can still find one. ~$200 seems to be a typical cost for something like this, but you're right... super hard to find for the Shadow series ... as most custom parts/accessories are.