There is a list of the MOXF's Waveforms in the product itself and in the DATA LIST Booklet (PDF). The instruments are mostly Yamaha instruments - the company makes just about everything you can name pianos, guitars, basses, celesta, harmonica, saxophones, trombones, flutes, trumpets, you name it. If you are talking about synthesizer waveforms - the only reference to brand and/or model is in the coded programmer's names - the code is not to difficult to break.

😉 Thank you, Bad Mister, for your answer. I received the data list booklet with my MOXF8. And indeed the waveform name is generally very clear (CF3 Flat Hard St- for example) and sometimes it is not (1360 Sync Lead1 for example).
It is not a fundamental problem for me. I just tried to find the right voice to start with when designing the sound of a particuliar known song (I play in a cover band). You can generally find the original instrument's brand and model used by the keyboardist on the internet.
So this post can be closed.