You cant really fix the via. the SE/30 uses a multi-layer board, and the traces back to the CPU is run in the middle layer. you cant see them. 

So, Sometimes you can stick a small thin piece of wire through the via, and tack it to the traces on both sides, snipping the wire off at the joint. IF... and only IF... that via still has a good connection back to the cpu. 

If not, then you stick a piece of wire through as I explained above, soldering it to both sides of traces, but leave the wire in tact and run it back to the CPU.