I'm sure at least on the later mk5 the anchor points were there under the seat, my dads next door neighbour has just sold one(mk5), now just has his 2l JPS mk2 capri.
Nothing like a modern car comfort, handling wise but do the job perfectly, not that noisy, a bit roly poly compared with newer stuff, but imo a better car than the capri, ghia's are especially nice.
My dads neighbour has had many of these, there is a website for the cortina as well as he is on it, so worth a look.
tabetha