How did the carpenters that originally built Shelley's roof know which bit went where? Answer - they numbered the joints. Using roman numerals, because they are made from straight lines that you can chisel easily, as this photo shows.
All Saints continues to give up its secrets as the new roof takes shape. The work is going well, with not too many surprises. Except, that is, for discovering one corner of the tower was being held up by little more than roof joists, and had dropped several inches over the years. (It's been properly reinforced now).
A mystery remains, however. Why aren't the rafters in numerical order?