[Hot Rod]

Hello all, my first post!  

I've had success with a handful of table tops but this bad boy is giving me a spanking! I have technical skills but am fairly new to toobs, mostly automotive stuff (hence the username).  I own a DVM with cap tester and basic tube tester, that's all right now.  The 690 receives ok on all bands (with my crap-o antenna).  Somebody has been in there before me.  Some lytics were replaced.

What I've replaced:

1. All lytics and paper caps, excluding any mica caps and anything under the IF expander cans.
   
2. All resistors except two buried in the RF chassis under the switch assembly, including the candohms with ceramics.
   
3. Replaced the X-over 1mic cap with a 4.7 film cap.
   
4. Changed polarity on one tweeter VC.
   
5. Cleaned and lubed everything.
   
6. Tubes test ok.  Replaced both 6L6s with Tube Doctor units.
   

What I've checked:

1. The 3 xfmrs and 2 chokes on the lower chassis ohm pretty close.  I have since read that I should have removed all tubes, which I did not.
   
2. Speaker wiring, frayed but no shorts or opens.
   
3. All 3 FCs and VCs ohm good.
   
4. Volume pots ohm good.
   
5. Tone controls pots ohm ok but treble does not go to zero on either end.
   
6. Checked and double checked my work, but there's a lota stuff in there! I could have easily missed something.
   

Symptoms are:

1. About 1/2 the volume that I would expect.
   
2. If you remove either 6L6, no noticeable change in volume.
   
3. As you increase treble (CW) the volume diminishes to near nothing.
   
4. Bass control functions but will distort sound at full CW.
   
5. One tweeter is lower volume than the other.  The lower volume tweet FC is cold, louder one is lukewarm.  This symptom follows wiring swap to the opposite tweeter.
   

I'm hoping for a little direction from you smart guys.  I was going to open the IF expander cans but thought I'd ask first as I don't know their function yet.  Looking forward to radio chat with you all!

Thanks!