The project site lists several advantages including faster re-works and it being easier to see what you're connecting, but that doesn't seem to be the case since all of the wires are crammed into little channels between the chips.
On the underside of the board there's more room to spread the wires out, making it easier to see the pins and to find the wire you need to re-work - usually you can trace the wires visually, especially if you do some color coding.
They don't seem to be too hard to find, Jameco and Mouser (among other places) carry them, a 40 pin socket for a Z-80 costs $5
In the UK, Farnell and RS components don't list wirewrap sockets any more; they both sell Harwin SIL/turned pin wirewrap strips - but they are not cheap and to create a 40-pin socket would cost something like £4.20+.
A 40pin IC socket from Tayda in Thailand is $0.13. Since I usually buy around $20-$30 of parts at a time, delivery to the UK for around $4 is not an issue.
Pin 1 remains at top left, as it will be in the diagrams on the datasheet, rather than having to mentally flip everything. That's the possibility I can think of.
When I started wirewrapping, I'd use a magic marker to place a dot at the pin 1 to make it easier to visualize on an upside down board.
For a while I did some wirewrapping for a company (defense contractor) and the boards came drilled and with silkscreened component markings much like you'd see on a PCB. It's not clear why they went through all of the trouble to silkscreen and drill boards for wirewrapping and didn't just make PCB's. Probably a combination of the cost to create PCB's coupled with a low production run (they were building 5 custom products, so a pretty low volume)
The project site lists several advantages including faster re-works and it being easier to see what you're connecting, but that doesn't seem to be the case since all of the wires are crammed into little channels between the chips.
On the underside of the board there's more room to spread the wires out, making it easier to see the pins and to find the wire you need to re-work - usually you can trace the wires visually, especially if you do some color coding.
They don't seem to be too hard to find, Jameco and Mouser (among other places) carry them, a 40 pin socket for a Z-80 costs $5