Thanks to both for the feedback, I will indeed give them an underseal
Got them out of Paddocks Sam; they had steal but I decided to get the Galv coated: I expected Brit part but they are unlabeled or marked so not sure: They are really quite good quality, good thickness and well made, I'm happy with them.
Paddocks item number is:
Left Mudshield - Galvanised (MRC6082GALV)
Right Mudshield - Galvanised (MRC6081GALV)
Steering Box Cover - Galvanised (330459GALV)
Personally i'd go the whole hog and get them t-washed and then a good coat of paint and then underseal, the more protection on there the better
If I was to paint as well which i dont mind doing. Would galv require and etch primer? I'm guessing it would Only because its the only thing I dont have in the cupboard