The examples at Gamlingay church in Cambridgeshire are considered at Gamlingay.
To the east in Suffolk are those at Lidgate, which I have posted about some years ago on this blog. Here the interest is that one might. just conceivably preserve the handwriting of local boy turned monk turned poet John Lydgate of Bury St Edmunds. This discovery is discussed in an article in the Guardian The message of love hidden in medieval graffiti. It is also covered in a piece on the BBC News website at Author linked to church graffiti
The Lidgate inscription is also considered in Lidgate St Mary’s ‹ SECRET SUFFOLK and in a post by Matthew Champion, the author of the first article that set me on this thread, on his blog about his work with the Norfolk and Suffolk graffiti recording project at Let's talk Lydgate...
Finally the theme is picked up and linked to manuscripts of John Lydgate’s poetry by the Library of Trinity College Cambridge in John Lydgate, Medieval Graffiti and Mythological Beasts