You could also look at the paper by Callaway analysing ayahuasca brews. Dont know how to post a link to it but if you type Callaway decoctions in the google search box for this site, you should find it. He gives an analysis of several brews from a few amazonian tribes, as well as Santo Daime and UDV brews, with the quantities of Harmine, THH, harmaline and dmt in mg/ml. So you could just replicate using extracted alks.

Edit: Found it.