Thanks PaulR and Analoguesat for your helpful comments, which tend to confirm my opinion of the Installation 'Engineer' .He certainly had no light touch when adjusting the Dish!
Question is what now?
Mounting the dish on a mast,itself mounted on the floor of the Loft , poking through the skylight opening, would prove ability to receive 2D, since I could adjust the Dish without getting on the roof myself. but a permanent solution will require the Roof to be pierced ,since passage through the Skylight opening is hardly an acceptable solution !! I don't think that idea will be acceptable anyway .Best try to find a more capable Installation Engineer I guess and not easy in this area ! See what comes of volunteering help!!!
Myself I live on the border between 47 and 82, and in this area I have actually installed a Small Sky Dish, in one or two locations, without problems ,although I normally
prefer to use an 80 cms Dish .
T1154
Ps T1154 is the age giveaway which Explains why I am forbidden to go roof climbing myself!!