TBH, they are a bit of pain to get out, and you'd be lucky (read very lucky) to find one a) not already rotten, and b) Removed in one piece and not bent, and in which case the truck you are looking at would probably not be for breaking.
As far as I know, the floor panels are not available for the later RRC, so I went and found a nice ali one from an earlier Rangie as per the write up above, and slotted that in instead -does the job nicely
You could make your own hatch for the fuel pump, but in all honesty I haven't, as dropping the tank is not a huge job, and that's how all the old ones were, so why should it be a problem now? The seat belt holes will need re-drilling in the correct place, but by using the 1991 seat belt mounts it is not a problem having a corrugated floor at all, they have enough of an upstand to clear the surrounding corrugations.
I understand this may not be the way you wish to do it, if going for originality, but IMHO it is a long lasting method of repair.
Oh, and don't forget to order a new rear body cross member at the same time!