for me it's the manufacturing processes that I sometimes struggle to understand - although I do know that the pontil rod is used to hold the piece whilst additional hot working is done etc. I also know what is meant by the pontil scar and ground/polished pontil depression. Obviously, as far as cutting goes, this is done when cold.
This piece looks an obvious candidate for being plunger pressed - so might the reason for having had a pontil attachment be because after pressing the rim needed to be fire polished.
Or am I wrong completely and was this a blown item which started life on the end of a blow-pipe, then rolled roughly to shape on the marver and then blown - to be subsequent transferred to the rod to finish the rim?? Just that to my ignorant eyes it didn't look like a piece of blown glass.
Sorry to be dim, and am sure one of you clever people can help me
By the way, what is a 'thumb' bowl??