'Worked' cases-questions??

That little area is called the transfer base. Usually it is blended to the cylinders transfer ports when you blue print an engine or when you do drastic changes to the transfer ports of the cylinder. But It looks like they just built up the transfer base by welding and machining. Hard to tell but it almost looks like they shape filled the oil pasege with epoxy before machining. Epoxy is used sometimes to change port timing and other things in engines. They did this to match to the cylinder work I'm guessing. Like I said it's hard to see what is going on with any of it without having it in hand at the shop. Hope this helps.

It just cuts down on the turbulance in the transfer ports.

Paw Paw