Your B+ reading is bothering me. I would rather is was a hundred V lower. I suspect one of two possibilities. One is that you have not drawn enough current to make the choke behave itself properly. The second is that you have some other HV than 250 hooked up.L-C filtering of ~250 vac should yeild ~200VDC.
Both are easy to fix. One requires only a few twists of R3's screw...
BTW, the current measuring method Colin came up with is so nice to use. Confirm current in-circuit, and with the B+ on no less.
But how does it sound?
regards,
Douglas