Weirdly, on mine, the sides were good but the fabrication with the 'pin(s)' that locate into the rear chassis longitudinals were rotted away. I made new ones for there, reusing the pins. The steel bumper itself is very thick and when I got the car it looked scrap but after removing it (that was a feat!) and a shot blasting it was still solid. The side extensions I would have fabricated something if they were scrap.
Got my first p38 2.5dhse 2022, but owned much simpler landrovers for 30 years , series 3 , sold, and also a 110 200tdi csw that I've owned for 20 yrs. Rebuilt it then on a new galv chassis and bulkhead. The p38 hurts my simple underworked brain especially electrical things.