I have had good luck with 3d printed venturies .  I model them in fusion 360,and I have used abs.  you will have to play with the insert and throat size to get the exact size you want.   I have only made venturis with through the crankcase spray bar holes and some with the drawbar holes. the above the crankcase NV placement may or may not work, as it probably is not rigid enough. I don't worry about using a o-ring as  my 3d printed venturis are pretty much a slight press fit.