Those Wolverine scans always look so awful.
No, never a frame blend. Not for nothing, nowhere, never. (Quadruple negative on purpose!

)
ProRes422, 720x480 -- what is the frame rate? Does it match the Wolverine scanner?
Film has no interlace.
Film is progressive, meaning "one after the other", which is what film does. One frame, then the next, and the next, etc, thousands of them.
Wolverines don't have great resolution, and I believe that interpolate as well. So if it downscales, it's not much much.
I've not used MPEG Streamclip in years. I know it has some non-core utilities, maybe even non-compression (non-MPEG), but I'm not certain. I'd hate to import file, compress it to MPEG (bitrate constrained, GOP, 4:2:0), then extract back to ProRes422. So you need to verify all that.
Why not use iMovie or FCP for such importing?
PS- Too bad that rotten scanner shares a name with one of the best Marvel characters.