I was wondering if Montblanc would use Minerva's famous caliber 48 movement, developed in the 1930's (I believe). Montblanc has already used, with acclaim, Minerva's chronograph movements from yesteryear. But the caliber 48 is "crude" or "blocky" in design when compared with their 13-20ch movement. I wondered if they would ever incorporate it. It seems they have finally done it! http://www.ablogtowatch.com/montblanc-timewalker-pythagore-ultra-light-concept-watch/ .
The 13-20 has always been something special, but the finishing nowadays is extraordinary. Not that fond of this 48 rendition.