Ah, okay. Is VLC something you’d rather not resort to using? I’m not really familiar with MPC, but VLC’s cropping has worked well for me when watching non-anamorphic widescreen DVDs/LDrips on a 16:9 display.
MPC-HC paired with MadVR/NNEDI3 is great (but very CPU intensive) if you’re upscaling content (eg. playing a 720p movie on a 1080p screen, playing a 1080p movie on a 4K ultrawide screen). I would recommend looking into it for playing your sub-1080p anamorphic content
VLC is fine, but not really ideal for regular movie playback. It’s not that I wouldn’t resort to using it, it’s always handy in fringe cases like this, I was just suggesting alternatives for people in a similar situation, but through discussion, I think a proper BD image would be much more useful than what I originally suggested