When researching editions of
The Pilgrim's Regress that are freely available, I come across 2 versions of the 3rd edition (1943?), which contain C.S. Lewis's notes on his re-reading his original 1933 edition. The
Fadedpage.com HTML version has it as a Preface, as well as a running headline (authorized by CS Lewis as he mentioned it in the Preface) that is very helpful to understand the allegory, but no illustration by Michael Hague.