You might be in luck. I've got a banged up NISMO bumper sitting in my garage. Might be perfect for the track since this is used and already kind of beat up.
I got into a fender bender recently, low speed bumper to bumper traffic. Other than that it's in great shape
. I can take a picture of it and post it here if you're interested, lemme know.
P.S.
I forgot to mention that I also have a stock OEM rear bumper available too for sale here
OEM Body Panels Front, Rear and Sides in Solid Red