There's really no such thing as a "traditional sichuan sauce" in the sense of a hot sauce since that's not how sichuan peppercorns are typically used in traditional Sichuan cooking. Typically, the peppercorns would be fried in the cooking oil to infuse the flavor and numbing qualities and then the peppercorns would be removed from the oil (though you can find instances that call for them being left in).
You're going to want to stick to cookbooks and/or YouTube (though I've found it can be difficult to find a variety of Sichuan chefs on YouTube). /u/HaggarShoes mentioned Fushia Dunlop, here's a great book of her's on Amazon:
My bf is going through the book Land of Plenty. With a few ingredients from Amazon that are a little harder to find if you aren't near a Chinese market, he makes simple hearty meals in 20 minutes. Most of the dishes take about 20 minutes.
With the exception of ethnic cuisines (e.g. Tibetan, Uyghur, Hui), there are generally four types of Chinese cuisines:
Eastern (Jiangnan area) - Land of Fish and Rice by Dunlop, Fuchsia
Southern (aka Cantonese) - The Wisdom of the Chinese Kitchen by Young, Grace
Northern (e.g. Beijing and Shandong) - Unfortunately, there are not many cookbooks on Northern Chinese cooking. The closest one would be The Seventh Daughter by Chiang, Cecilia, but you can read the top Amazon review, in which the book instructs to use aluminum foil instead of lotus leaf for the Beggar's Chicken - not very authentic. I personally own China: Peking and Shandong, but I haven't gotten around to using it yet. Probably not authentic, though, as it was produced as part of a Time-Life Cookery of the World series.
I highly recommend you this book if you already have sound basics.
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https://www.amazon.com/Land-Plenty-Treasury-Authentic-Sichuan/dp/0393051773
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Were i for you i would go to Chinese markets and restaurants and talk to the chefs there if i like their food.
Recipe was taken from Fushia Dunlop's Land of Plenty cookbook. The noodles I made by hand, using a recipe from the China Sichuan Food blog, though I used the udon method of kneading - which is to say, stepping on the dough :). I think the biggest mistake I made was adding way too much Sichuan pepper - definitely a bold flavor!