The section on the Nelson CD was:
Tuba:
Alex Cauthen, Holton CC
Ed Jones, VMI rotary Neptune CC
Euphonium:
David Strand, Yamaha 321
Brian Davis, Hirsbrunner
Glad you are enjoying the recording. For sheer sonic impact, try the Pomp and Pipes recording. Especially the last few minutes of Polka and Fugue from Schwanda the Bagpiper.