Arkansas Valley Diesel has been mentioned on the forum previously (I believe they're actually located in Colorado, however). It appears that they've had several Ebay auctions for that part and one very recently. On one page, it says they are out of stock but yet on another, it says they have 2 in stock.
You might call them to see if they have any available now. The attached screenshot shows a page that was featured less than two weeks ago. Also attached is their contact info.
Here's the Ebay page from back in June: FREIGHTLINER PEDAL AY,TILT/COLUMN RGT-452262X2
eta: they do describe the item as OEM Freightliner