Hi Mark,
I think older DACs have gotten an unnecessarily bad rap in this age of higher resolution audio, and a number of these older DACs, on 16/44 CD quality recordings, still sound quite wonderful. To give an example, my reference DAC is a Stahl Tek Vekian Opus. However, I also have both an EMM Labs DCC2 and a Dodson DA-217 MkII.D. While the Vekian is clearly the highest performer (at $35k retail, it better be), both the EMM Labs and the Dodson acquit themsleves quite well, and I in fact prefer them to a number of the newer DACs that are getting a lot of print these days.
Of the DACS you mention, my experience with them is quite dated. I was not a big fan of the Elgar at the time, finding the EMM Labs superior (more natural presentation with more air surrounding instruments, for example). I really did like the Spectral combo when it came out, but this experience goes back more than 15 years. I don't recall hearing the ML 360s, but did hear the 30 / 31 combo on a number of occasions, which I enjoyed as well, although I recall preferring the Spectral combo.
In short, I think there are some great older DACs out there, and encourage you in your search. The EMM Labs in particular, at their current prices, are ridiculous bargains. (And don't get me started on transports - if you are still spinning any discs, most of the actual transport mechanisms still in manufacture today are poor quality).
Best of luck.