The 8 inch Advent woofers are pretty common. These were also used by Dahlquist (my Dahlquist DQ-12 has the standard Advent woofer). Advent used the 8 inch drivers in the Heritage, Prodigy, Prodigy II, Prodigy Tower, and Graduate. My assuption is these are all the same driver.
The Heritage is a great sounding speaker.
The Heritage is considered a 2.5 way speaker, the bottom woofer crosses over at a different frequency than the top woofer. I have a schematic of the crossover if you need it.
I enhanced mine with additional sound insulation, metallized polypropylene capacitors, and upgraded inductors. Its one of my favorite speakers.
ChaddarHeadG - if you start a thread on the wood splitting, I'll share what I did with my Advent Legacies, and discuss options as I have a related problem with a set of Laureates.