Yeah, that is a rebuilder tag alright. (Sorry, no idea whose ...)
I would expect that "Z 2730 D" would be a part number used to identify the intended application range, and the numeric number would be a unique serial number used by the reman for warranty and build records, etc.
I googled that and found the same "Z 2730 D
" tag with a different serial #(114468),
and also found a "Z 2730 V 128375
As far as identifying manufacturer and specifications, most remanufaturers and/or engine parts suppliers will indicate, at the least, oversize or undersize information right on the part. The remanuacturer also generally stamps dimensions on the block and crank. (i.e. 030 010 010 would decode to .030 overbore, .010 undersize on the mains and rods. Pistons are also usually stamped on the dome. (eg L2377.030)