The wk-3000 'built in' tones are part of the hardware...so you cann't 'lose' them. I'm not familiar with the w1700. It would have to be compatible with the 'ckf' file format, and use the same 'Zpi' tone generators, and be able to load samples. I'm thinking that it wouldn't not be compatible. The wk3000/3500, and ctk691 all have the Zpi tone generators...and the mz2000 was the 'high end' keyboard, with a 'souped up' zpi (4 tone generators instead of the wk's 2). Tell him to trade off his w1700 and get the new wk's
We have another active wk/ctk user site at http://www.originalz.com/casio/casio_bbs/
We have hundreds of converted Roland rhythms, new tones, and user songs...for free sharing. The Casio download site also has lots of good downloads, to fill up your 'user tone' area. http://music.casio.com/e/data_ex2/