Glidden was taking raw castings and almost re-casting them so he could make the chambers the way he wanted them. He had an oven to heat the raw iron castings so he could braze them up and re-machine them to his liking. Not sure if he was doing that for the W2s but definitely for the Ford stuff. It was not surprising but still eye opening to see the lengths he went to.
I learned about all that from this video below. The guy making the videos is kind of obsessed (in a good way) with Glidden Pro Stock History. He goes pretty deep into some stuff.
