I can only take some wild guesses. As far as I know, the Streetly collections for M-Tron Pro and the Memotron are the same, but in different formats. I think the M3000 samples are probably the same, but maybe half or quarter the sampling rate to make the files smaller. After all, it doesn't make much sense to sample the same Mellotron three times for three different applications when you can just manipulate the same samples.
Bernie
Bernie