New DC-3 issues

[Friar]

I recently purchased a DC-3, and after dealing with some of its issues, I thought post them here to see what suggestions some of you may have.
 Mine is an early model (400s SN), and I replaced the power tubes with JJs, and replaced the speaker with an Eminence.

 My 3 ongoing issues are:
 1. I'm getting a rattle from the reverb tank, but don't see anything in it that would be causing it. It buzzes with certain frequencies, anyone else have such an issue?
 2. What are the big black plastic pieces behind the EQ sliders? The one behind my 80hz is loose. Is that a potential issue?
 3. I have a 2-switch foot-pedal that works well for the reverb, but the EQ is unresponsive (yes I have a stereo cord), any suggestions?

 I guess I'm a true 6L6 guy, because I'm struggling with loving this thing. My MKIIC has long been my standard, but I'm trying. I have been pleased with the clean channel setting I've dialed in, but sadly unimpressed with the overdrive.

 Thanks in advance for any suggestions.

 

[Don]

The plastic pieces behind the EG sliders are inductors. If the 80hz slider works at all it's fine. Mine was missing that inductor and the 80hz slider did nothing and the amp sounded thin with the EQ engaged. I ordered a new inductor from Mesa and installed it myself. It was a pain in the butt getting the GEQ board out!

Do you have a multi meter? If so, test the footswitch and cord to make sure they're working. You could also use a powered test light.