I think you mean, What is Landrace like?
The stuff that grew 20+ years ago still grows today in the country it originates in normally, What your talking about is the Skunk Hybrid such as NL, AK and other big names we know of.
Hash's such as Blonde / Red Leb, Afghan, Nepalese, Indian, Pakistani, Marrocan and Brick / Block (Compressed) Weeds such as Jamaican, Thai, Columbian, Brazilian, African and Oil (Not Butane Extracted Honey Oil, Proper Indian/Pakistani Oil) should usually be made with Landrace Plants and should be the same as they were 100 years ago I would imagine.
In my experiences these hash's, compressed weeds and oils made from landrace strains differ in effect greatly, from immense highs to unimaginable Stones! Blonde Leb, Marrocan and the compressed weed give a high normally and the other hash's and the oil give a stone.
What do you mean, "Is THC a chemical messenger?"
Could you explain this a bit better?