Welcome. I would call your local RV repair shop and see if they can order you something that will work. The color may not match exactly but you could always paint it black or white to suit your needs.
How bad is it? Perhaps use the RV for a year or so. It will be your "Practice Bumper".
2017 Axis / 25.4: Big Foot Levelers, Aims 1200 Watt inverter, Ceramic Window Tint, Full River AGM 6V batteries, Front Hellwig Sway bar / Rear Track Arm, Safe T Plus Steering Stabilizer, PD 4655 converter, Hard Wired Surge Guard, WEboost + WiFi Ranger, LED Headlights/Driving lights, TPMS, Surge tank, Tornado flush, Viair Compressor