582 Serial Number Question

The shop I am working with received a 582 engine for a block replacement. The new block has no serial number data plate but does have an inscribed number (appears to be a serial number). The block part number is 300058205, but the inscribed number is 7942708. Is that the serial number of the block or will that be the new serial number of the engine?  According to the IPC that part number block applies to engine serial numbers 9619116 and subsequent.  

I am confused six ways from Sunday on this as this is a new block, but not all the internal parts were replaced.  This isn't exactly an overhaul either?  Do I transfer the engine data-plate from the old block to the new one? Please advise.

Thanks and Best Regards to all!