For VHS there's the VHS-Decode project that's trying to do something similar. I don't think they work by scanning the tape itself with some custom hardware, but rather by recording some kind of internal RF drum head signal inside the VCR itself. Then they have a software stack to decode the VHS signal into actual video. Looks pretty cool, but I've never used it.

https://github.com/oyvindln/vhs-decode