what about:
clock 750
8 bit
video aspect normal
video sync off (try normal too, didn´t see much diff but on sound off it goes too fast on off)
frame skip 1
sound 22khz fast (can use lower but starts sounding strange)
cpu 90%
audio 50%
asm core none
ram tweaks on
I still don´t get what I get from my desktop, but it is kind of close. Any better performance on your side on that?
Bad thing I just deleted last mame version, try the last version too just in case.
edit: can´t clock higher on my end, freezes, but before that, the 800 seemed going a bit better. Must find a way without any OC, it does not seem like a game that would require soo much.
Let me know how it goes!