I have just read the same article and we have done quite well with Pine Marten spotting on our visits to Scotland.
In a rental house in Torridon in 2009 they were regular visitors during the day and ate pretty much anything as you can see in this photo. They liked jam on bread and that's bird seed on its nose. They loved fresh strawberries and even jelly babies (we only tried it with a couple).
We were amazed to see one in the rental cottage in the middle of Glencoe last year. There is only a small patch of forest around the house and I was wondering if it was an isolated group or if they travelled cross country. I put piles of peanuts out the first day we arrived and they were all gone the next morning. We finally heard and then saw the Marten very late on the last night of our week.
More amazingly this summer in the rental house near Aviemore it was mid-evening and we were in the house with the patio doors open and heard a noise by the kitchen bin. It was a Marten looking for scraps.