I loved this series when it was first broadcast and introduced my wife to it about three years ago thanks to the boxed set. It is a real gem.
I enjoyed your review although I have to say I enjoyed Allo! Allo! from the first time I watched it. I think part of my enjoyment was knowing it was a parody of Secret Army and, as Mr. Caine would say, not a lot of people know that.
I was interested in your comments on Kessler. I have been thinking about getting it but have reservations.
I'm currenlty reading Matthew Cobb's history of the Resistance in France. It is simply calle "The Resistance". The accounts in the book tell of the same atmosphere caught by Secret Army, albeit in Brussels.