Following a hot tip, I was able to locate a MB ticket at cost last week via Nadine at the Le Mans tourist office. You can enquire, book and pay online.
Worth a try!
Doug
Below are details of tickets available.
Beauséjour
46 €
8 €
Bleu nord
51 €
8 €
Expo 51 €
8 €
Houx annexe
51 €
8 €
Karting nord 65 €
10 €
Tertre Rouge
81 €
15 €