First of all, you ought to secure a few corbels. It should not be so hard as it seems, as corbels have been widely spread in house structures for some centuries now. Mainly they were used for roof supports, but depending of the design, an individual can find them as flooring supports as well.
Consider searching for nice dilapidated houses. I man houses that would be fine if they weren’t dilapidated. Old style design, mostly. They’ve a whole lot of corbels. Or you can go to some city honest or estate auction, where they sell everything really very cheap. You will certainly find one.
After you have the set of corbels you may want to do a little refurbishing on them. And by that I mean a proper painting and sanding. And an eventual professional cleaning to be able to remove wood parasites, if any.
Next you will need a glass top. That’ll be the actual length of your desk , so select your own value. The width of the glass top should be the actual width of the corbels. Because the corbels will be connected to the wall and thus be the desk’s toes, the glass top will be secure on top of them. So the width of the corbel should match the exact width of the glass top.
I suggest choosing a thick glass top. Not just it’s safer for you but it is also looking better. The corbels are sturdy thick pieces of work, so using a thin glass top on them will look very flimsy and out of proportion.
For securing the corbels to the wall I suggest using some corner mounts. You can fix them in four areas each, two in the top and 2 at the bottom, which will give a tight and most of all a secure fit. If you are not a fantastic hand with drilling you’d better ask a friend who’s to do it. Next set the glass top and secure it in place with anything. The gently drill four holes in it. Two holes along the left margin, two along the right, and use a screwdriver to fix it in place on top of the corbels.
There you have it: it’s as unique as corbels get and I bet you friends don’t own one.