Looks like there's a relatively affordable silicone pinna on aliexpress these days. Will not have the same tolerances in terms of QC as a GRAS rig but it's also less 180 dollars instead of 7000 dollars. Someone even made a 3D printed plate for it. https://www.youtube.com/watch?v=X0Wl5NChYfI
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Well if you want to try it out I recommend using https://squig.link to upload your measurements and well regarded ones to compare and gauge how useful the pinna is. The site is useful as a graphing, comparison, and EQ tool even if you don't have an account.