Selur's Little Message Board

The original movie was shot on PAL video, 25fps interlaced (early 1980s) and was then converted to NTSC for a US VHS release.

I've bobbed the NTSC VHS capture to 59.94, and I've tried numerous settings in sRestore to get the frame rate back to 50 progressive, but I'm seeing dupe frames throught - although the field blending is being nicely removed at scene changes, which is the main purpose for doing this.

If I set sRestore to 25fps the output looks fine, but then I would need to interpolate to 59.94 as this is what's required for the final interlaced 29.97 Blu-ray. I'd rather interpolate from 50 to 59.94 as it's less obvious.

Am I missing something that would enable sRestore to 50fps without dupe frames?

sRestore should try to:
a. avoid using blended frames
b. prefer using unique frames
but it will prefer adding duplicate frames, when I can't find unique frames over using blends.
Unless your bobbed source has 50 unique, blendless frames in it every 59.94 fps, there is nothing sRestore can do.
If tuning the settings and maybe addong some denoising before sRestore doesn't help, there probably is nothing sRestore can do.

Cu Selur

is it possible to get a short clip of the raw video.  I would like try a different approach to it.

Sure - sample clip here.

try: moving ReduceFlicker and SDeflicker and similar before sRestore and lower the speed of sRestore.