The files be gone broskies and siskies... What's up with that?
I can't speak to why current forum links don't work but consider that the LABsub project is 16 or so years on... I'm surprised anyone is still building them. When Tom Danley designed it, the LABsub was a proof of concept that a (for then) high performance, tour-grade sub did not have to cost US$6,000+. Tom modeled it in a couple different software packages (HornResp, the other I've now forgotten), got Eminence to build the 12" woofer, and much sawdust was eventually made.
Tom's horn design still stands for its intended woofer(s), but transducers have come a long way since then and there are other DIY sub designs for new woofers that will outperform the LABsub by +6dB or so, or more than equal it with less construction difficulty.