The great thing about that recording is that it sounds exactly like they really sounded like. I've always done pro and amateur choirs and orchestras and that one for a school is very decent - the arrangement is good too - the unison suddenly splitting and that's managed very well but the choir and the conductor/leader. Sure, it's got the characteristics of vinyl - the surface noise and 'feel', but that also paints the period. It would be good to see if it can be cleaned up. I found an old live recording a while back but it's an archive copy made from a random mix of mics on the live boards unused aux outputs. It sounds far worse than that! Good job. I'd definitely see if you can go further - the choir is worth it.