The differance between MFSL Ultradisc I and II?

I believe the two version used their GAIN recording method.

Thanks for the responce Qdrone!

However, how can you tell from the ouside of the box if it is an Ultradisc I or II?

The CD longbox (Remember those)that I have just says Ultradisc on the front.

The I's are more rare than the II's. I prefer the I's over the II's for better sound. The difference is that of being pressed in the US (I's) verses that of being pressed in Japan (II's). The first versions were also aluminum verses that of gold..........

There is no such thing as an Ultradisc 1, there are simply the original Ultradisc reissues and the Ultradisc 2 reissues. Your reissue, from 1991, is in the original Ultradisc series. It was never issued as an Ultradisc 2. For your convenience here is the Mobile Fidelity discography, that verifies this, http://members.aol.com/boardwalk7/mofi/mofiulcd.html

To answer your other question, the British LP is the copy preferred by audiophiles that have made the comparison.