I’ve posted some images of the art in Cairn T and have tried to tie these in to published plans of the cairn. The difficulty here is that two numbering systems have been used in the past. These are published in Shee Twohig’s The Megalithic Art of Western Europe and Martin Brennan’s The Stars and the Stones.
Both use the same system for passage stones – L and R for the stones to the left and right as you enter and numbered from the entrance – but different systems are used for the chamber stones.
As the Brennan publication is more generally available (and is used on some other web sites), I have concentrated on that one with the Twohig number in brackets.