Interesting thread and information, outside of the drama I have enjoyed browsing while reflecting on the remnants of the landrace and the availability. Be it private circles, open markets these remnants by majority are just this. Without a really good sized open pollination each generation loses genetic diversity. With this said just about all of the remnants are nothing compared to what they were in the natural environment and a population.
I have been pretty fortunate in life having learned from the land races of yesterday eventually finding my first hybrids within import from Mexico after the Indicas were pushed upon the farmers and it flooded into the states eliminating the old summer drought we always had to deal with waiting for the fall harvest's.
My father was selling pot ever since I could recall and it was interesting seeing the many types he would try to grow behind our house, even though most of these really good seeds were from even further south than the typical Mexican he sold. Having that mob connection allowed him to always have a limited supply of South American varieties even though none of these would actually even flower this far north. It was not until I was climbing 14' Afghanistan plants that I realized how important they were unlike the ones he usually sold by the garbage bag of leaf. This really helped me to better understand how diverse this plant is early on in life well before I began to grow myself in the late 80's. Since the late 90's so much more has changed then just that forced introduction of the Afghanistan into Mexico I mentioned.
I have been working with a lot of very refined land races the past ten years or so while really only finding true diversity within the African types predominantly.
I know there's a few good people traveling and seeking the rarest in places like India as example, but they too all too often bring, or send back adulterated stock all too often contaminated with Afghanistan/Skunk genes, no different than the King demands for more hash production with the introduction of Moroccan plants and the infusions within the Indica/Kush Afghanistan types.
recently I witnessed this Sar Hawza said to be a rare Hindu Kush brought back after being found in the mountains actually be tagged with Skunk by Phylos, even though it actually had a wide range of mountain Afghanistan hash plants or highland as some say within the genomes. Out of several different people to run that "Sar Hawza I was the only one that actually found a Kush type , even though it is more Kashmir like than Hindu. Most of the other looked a lot more like Moroccan then Afghani..
These are just my thoughts and two sense and examples. I think I can actually agree with the scientific community stating that there's no such thing left as a pure cannabis type( outside of what I have been working with straight from Africa.)