If one was inclined to hunt through the Desper thread (there's 51 pages!), he mentions something about them marking the tape with sellotape so they could identify overdubs, or something of that ilk. While in theory a helpful idea, after 40 years the chemicals on the sellotape affect the actual recordings...

however, they also said that when it was mostly nothing they couldn't handle

This may explain why we haven't had much more Sunflower stuff.