Thank you for the advice. I have been in touch with the frame builder's son and although my Italian translation is pretty bad, he tells me to leave the varnish on the decal for at least 30 minutes. Then place the decal on the frame, pressing down hard working from the length of the middle portion outwards in both directions. He then tells me to dampen the backing paper and peel it off, starting from one corner. After this has been removed press down hard all over again.
Then this is the bit I don't understand. He tells me then to use water to thoroughly moisten the thin backing paper and carefully remove that, at the same time pressing down on the decal to avoid it lifting.
It is then necessary to leave the frame for at least 48 hours to allow the varnish to dry thoroughly. Only then should you use "fuel" whatever that might be - but definitely not petrol, to remove any deposits, including base adhesive from the face of the decal. If you don't do that, eventually the decal will crack.
After this has dried, it is suggested that the decals and frame are clear coated gloss varnish.
Just to complete this excursion, he suggested / told me to paint the frame Ferrari red - no other red ! So, to comply, I found the Ferrari paint code FER300 for the period and Halfords have duly made this paint up for me, in spray cans. Strangely, the paint is made up from three different shades of red, purple and white ! Chirico red frames should have yellow paint in the engraved / cut-out letters / lettering I'm told. So now I seem to know the full story, unless you know differently !
PS. being a [doddery old] computer cretin I've no idea how to eventually include photographs, which I can just about manage to put in "My Pictures" !