Stretch,
There are a number of pitfalls involved with just milling these antennas, Yes some of thie information is in the public realm but there are quite a number of issues that had to be dealt with and the calcs have to be refined so as to provide the gain we are getting from ours.
I have tooled up to manufacture these on a reasonably large scale and could be persuaded to provede them as either partillay finished ot finished items at a reasonable cost. I have allready ironed out many of the issues and we get a 1.2:1 VSWR as they sit.
You may want to check out the specs...
http://www.borg.net.nz/docs/8slwg.pdf
Regards
Andrew