Worth a call to Scillies ATC, they are a real friendly bunch, and will give you a quick brief prior to your arrival.
Def worth a quick flight around the islands before you land as its such a beautiful place.
If you coast out via Landsend make sure you fly over Sennen Bay as this time of year you may see a Basking shark or two!!
Have a great trip.... wish I was coming!!
Post some pics if you get chance.
S