Here is the email reply
I actually flew into Islay next door - you can catch a taxi to the ferry and get lift the other side. However, if as I suspect you want to go up in your Robinson, then there are 3 options - Islay, the airstrip on Jura itself - N end of Bay above the town, 400m grass next to the beach - E-W direction OR you could try ringing the Jura Hotel and see if there is a flat area near them - the front lawn will be full of tents!
I'll do a 'rotary recce' next time I'm passing (April) and report on the state of the 'runway'