Let me just add my two cents:
I just burned a Centris 610/650 ROM (checksum F1A6F343) onto one of my programmable ROM SIMMs, and it boots my IIci just fine. I think there's actually a fairly good chance that it would work on the SE/30. The fact that it also boots a IIci makes me think it's likely it will work. Unfortunately, I don't have an SE/30 here to test with to prove it.
Edit: I would try it in my IIx (which uses the same stock ROM as the SE/30), but I'm having trouble getting my IIx to chime with its stock ROM right now--another trace has probably gone bad on it since my last test.
I just burned a Centris 610/650 ROM (checksum F1A6F343) onto one of my programmable ROM SIMMs, and it boots my IIci just fine. I think there's actually a fairly good chance that it would work on the SE/30. The fact that it also boots a IIci makes me think it's likely it will work. Unfortunately, I don't have an SE/30 here to test with to prove it.
Edit: I would try it in my IIx (which uses the same stock ROM as the SE/30), but I'm having trouble getting my IIx to chime with its stock ROM right now--another trace has probably gone bad on it since my last test.