Not sure what the STG meant...but it looks like a pre-MB1 model...called the 'Traditional' model...
It could have been refaced...check out the baffle...whether it has Dave's diagonal handfile marks.
Take note that Dave often customised these early pieces for individual customers and so, each is unque in itself.
It could have been refaced...check out the baffle...whether it has Dave's diagonal handfile marks.
Take note that Dave often customised these early pieces for individual customers and so, each is unque in itself.