About 15 years ago, I had made another version of this using a readily available rubber boot bolted to a custom machined aluminum flange. I only had the G-Code which would not import using any tool I tried. I wrote python code run in FreeCAD to convert the cuts to draft lines then reworked from there. The carburetor is not only at an angle top to bottom, but also slightly left to right making it hard to take measurements. I was now able to blend (loft) all the way from the carburetor to the reed block port for improved flow.