Description:

Need crack-free re-buildable cores, with decent seats.  Require no-crack certification and a matched set.
Don't even think of suggesting heavily rusted, damaged or defective cores.
Of course, normal rebuild will occur, but if the machinist says they are junk - you won't get paid!
Credit Card payment only, and I will cancel payment if you screw me, plus you get stuck with shipping.
You will package appropriately and protect machined surfaces from shipping damage.
Grouchy old man.