Unlike the Hermes being a rust bucket when she returned , Illustrious seemed to be in prestine condition on her return, I am positive the date on the photo is correct, the Falklands compagne was between March and June 1982.
I think we both need glasses, if you have another look at the Cardiff and Exeter of which you posted to, you can see Illustrious in the background, the Photo was taken seconds apart....
All the best
Oh yeah! I was just checking in some old books and I saw Illustrious's commission date was only 20 June 82 and she didnt leave Portsmouth until Monday 2nd August, taking over from Invincible on the 28th August.
Not sure when they were actually fitted. I think she had them installed whilst being fitted out at Swan Hunter on the Tyne from what I have seen in some pictures. The 2 locations were covered by big tents whilst they were being put on. I did see a picture in Ships Monthly years ago of her at sea without them. She might have been on trails and then returned briefly to have them installed before commisioning.