Joel Hruska said:
Seriously, Frank. In no way am I trying to either imply you are unhelpful or crap on your expertise.

Never mind, so didn’t I with yours. Maybe my English is not that good, and you feel wrong subtle “vibrations”, not meant. It is not really easy to help, if someone of high intelligence like you is in the job for months, already did hundreds of experiments a. s. o.
But in spite of this you - sorry - seem not to really understand what really happens with the original 24fps-film when being pulldowned.
Ok, you see RELATIVE smooth motion in your 60fps result, because you use interpolated frames, but this artificially extended motion cannot be really smooth, it’s sometimes faster, sometimes slower. This can’t be called “stutter”, ok, but it is not the original smooth motion, where one frame of the original celluloid-film is one frame (or at least a multiple of one for EACH frame) in the end result. This is simply not possible, if you have 24fps film and 60fps end result.
Pulldown is done by doubling several fields (several ways to do so, doesn’t matter here). These have to be decimated to get back the clean progressive, original content, which is necessary to fill the AI upscaler, and to get really smooth and good results.
Your interpolated frames are not really good anyway concerning picture quality, but make also motion slower and faster.
Just the portions where you might have native 29.97fps, (interlaced or not, not important because you deinterlace), will work, because there you have simply doubled frames, when going to 60 (59.94)fps. This is smooth, ok.
I don’t think, it’s the way to go, to keep any double frames, and even worse to add interpolated frames to make it a bit(!) smoother. So your decision to get to 23.976 was the only way to go.

Again: If you like to see a IVTC-by-hand-script, send me some portions of the NTSC-DVDs. Also the opening credits are interesting for me - is this field-shifted? Interlaced? Pulldowned AND field-shifted?