"N" Suffix = plastic DIP package
J, K and L are non-linearity (accuracy) of the recreated sound - J = cheapest, least accurate, L = most expensive, most accurate.
Odds are your ears won't discern a difference between the three in a pinball machine.

What is the one you currently have installed? Should have a J, K or N.
Parts with higher temperature range (typically "D" suffix or ceramic DIP package) have an A, B or C within the suffix or an S, T or U within the suffix.
A = J = S
B = K = T
C = L = U

Also, before looking at the pricey DAC - look at the small value electrolytics first. Particularly the 1uF caps in the otuput section as well as the speaker coupling 1000uF cap.

PMI semiconductor (PMI prefix) -- bought by Analog Devices many years ago hence the current AD prefix.

Actually the capacitors are cheaper and much easier to replace than the IC.
Based on the age of the board - you really should look into that.