Ok, after trying those settings out, I finally figured out the "right" way to do it! Within the Env menu, you can adjust the ADSR settings for the Filter, thereby setting how quickly it cuts in after hitting the note and then changes after the initial attack. With a bit of tweaking of those settings and the base Filter params, I can get pretty close!
Actually, I started with the PPG Syn PS patch, from one of the free sound collections on the Access site. The final sound isn't that much different, just a tighter ADSR envelope, different filter cutoffs and less bass EQ.
P.S: The Phaser does actually help, but I'll tweak the settings without it first, then add it back on top.
Cheers,
EG