JCM 2000 OPT troubles?

[clyde]

DSL 100, came in with a blown HT fuse, complaints of no volume.  The preamp tubes were done, replaced but no joy.  Biased at 68mv at the terminals, 8w per tube, the EL34's redplate while playing, no headroom, much mush and distortion.  I have 477v on the plates, 466v screens, app. -44 on the grids.  Measuring the OPT with my meter I get 8R from one side to CT, 16R on the other, 25R across the plate leads.  I'm suspecting the OPT.