Didn't seem too onerous - fill the big holes with the right sort of ballast, and roll out a few pieces of Class 30 or 60 over it. (I suppose that must be the "kicking tin" you mention ?)
Fill the small holes with a version of Araldite out of a cement mixer.
Installing RHAG - Rotary Hydraulic Arrester Gear - was interesting to watch someone else doing.
39 seemed to be good for careers too, every officer was MICE at least, and all SSMs were WO1 Clerks of Works.
It was called EM2 matting IIRC. Came in planks about 6’ x 1’, they had to be slotted in place one at a time and then stood on to get them to lay flat. I did it once, in 1983. Boring as ****.