Personally, I don't know anything about them. You may find more info by searching for Oriental Gamefowl here on BYC and the web.I got a pair of Shamo from a coworker who has lots of Thai chickens. He gave me a pair from what he says is a prestigious line called "Red Ruby" Do any of you know anything about these birds? He told me that they're a champion breed that they keep in their tribe and fetch a big price tag. Said he wanted me to take them and breed them as he liked what I do with my other birds. I asked what the standards were and what to breed for but he just said to go big and strong and try to get faster.
TIA for the help!
You could ask Pyxis in the thread linked below if she has any info/tips.
https://www.backyardchickens.com/threads/the-ko-shamo-thread.1278977/
A lot of times the best information comes from whomever you got them from. It sounds like your coworker has been raising them for a while so ask him questions.
You may find these interesting/helpful as well.
https://www.feathersite.com/Poultry/Games/Shamo/BRKShamo.html
https://www.amazon.com/ORIENTAL-GAMEFOWL-Sportsman-Poultryman-Exhibitor/dp/1420876813