In general vinyl rips will have an altered frequency response than the original tapes. However, the exact variations will depend on the equipment that was used to rip the vinyl.Vinyl rips also have low-frequency rumble noise from the turntable, but again the degree and character of that noise will be different on different equipment, and it'd be difficult to distinguish that noise from tape/studio noise that's in the recordings anyway.Add in the fact that these rips have almost surely gone through some post-processing - nose reduction, pop removal, additional EQ - there's just too many variables to make that determination with reliability, especially not in an automated way.
Thank you all for the replies.I have some experience with digital audio restoration techniques using DART computer programs to compensate for peculiarities on my vinyl records, so I have some understanding of what you are writing. I was hoping that a simple frequency analysis program would establish the source, but it sounds like it is more complicated than that. I don't have access to any specialized hardware so I will have to rely on my ears and listen for clues. What I might do is e-mail the cd label and ask them to clarify.