On the schematics, it's clear that no dipswitches are used if the YM2413 is used in lieu of the AY-3-8912. So I'm going to assume they're not strictly needed. I didn't find any bits of dips at the bottom, so I'm pretty sure none were there before. Also, 16 less corroded-as-hell holes to clean out...
All the stuff game in, and I'm done re-populating everything (RAM, EPROM, xtal, amp IC) except for 1 axial ceramic cap in the audio section (C63). I'll deal with it later, if this thing is close to running...
Work is now focused on running Kynar jumpers for all of the corroded-through traces and vias. 5 down, 5 to go...