Well, that would put the master tapes at approximately 39 years old. I'm betting their condition is less then steller. What I would hope for is that someone took their time and with great care, dumped the original master tape 2 track, high speed masters into the digital domain. Many of us that still have reel to reel tape know that they age, the oxide slowly comes off, the "magnetic" properties slowly fades away. I think there was no other way to preserve these treasures.
If it's any relief, I've bought the Pink Floyd "Echos" greatest hits 4 LP box set on 180 gram vinyl. It's all been digitally remastered. It sounds pretty good, considering some of the songs have Sid Barrett on them, which makes those tunes real old.
As far as DSOTM goes, I have 4 copies. The crown jewel of them is the one by MOFI and this copy has been played 3 times; there are no pops, ticks or anything offensive. I have the 30th aniversary copy too. the other 2 are original releases in various conditions.
I just bought David Gilmore's album (twice) "On an Island", it is fully digitally recorded and is also one fine sounding LP. I am not in the camp that says LPs have to be analog to be good. I believe and have examples that it just aint so.
Wayner