[MrFixr55]

Hi Curt,
Congrats on your progress so far.

+1 on Terry's Advice.  The original caps were likely "wet" electrolytics.  Like Terry said, the negative terminals of Caps 37 and 38 don't go to ground, they go to the center tap of the power transformer HV winding.  That blue cap likely parallels one of the yellow Sprague jobs and does not need to be added.  Remember, if the speaker is being replaced by one without a field coil, you will want to up the value of the capacitors to 20uF, or maybe 30 uF.

There are a couple of ways to go here, all electronically correct.  What technique you use depends on how original you want the chassis to look.

• The Restored Look-  Obtain 2 original caps from a junk set of the vintage or post a wanted ad in the Phorum.  Follow the instructions in "Restoration Tips" for stuffing electrolytics.
  

• Alternate Restored Look- Obtain 8" of 1"OD copper tubing and 2 1" copper tubing caps from a plumbing supply, Home Depot or Lowes.  Cut in half with a pipe cutter or have the plumbing supply cut them in half.  Mount in the brackets where the 2 Spragues are, either with fish paper or a layer of electrical tape between the bracket and tubing.  From the underside, place the new caps inside each of the pieces of tubing with suitable insulation or RTV to hold in place.  A 1" rubber cap or stopper can be used to close the bottom holes if desired.  Put holes in this cap to pass the capacitor leads.  Since you will not be able to see the capacitor markings when they are in the copper tubings, color code the leads on the capacitors with marker, heat shrink tubing or wire insulation.  It is not necessary to actually solder the negative terminal of the capacitor to the body of the copper tube unless actually desired to do so, however, the negative lead of the capacitors must be correctly connected electrically per the schematic. Bend "eyes" onto the end of the leads of each capacitor.  Transfer the wires from the Sprague caps to the new caps one at a time.  Place the copper caps on top of the copper tubes.  These "capacitors" will look a lot like Marshon electrolytic capacitors.
  

• The quick and dirty-  Obtain a terminal strip with at least 3 non-grounded lugs and a mounting lug near the center of the strip.  This lug will be used only to mount the strip.  do not connect any wires to this lug.  Install the capacitors onto the strip.  The negative terminals of the capacitor should go to the same lug, toward the center of the strip.  The 2 positive terminals should point towards the ends of the strip. Transfer the wires one by one from the leads of the existing capacitors to the terminal strip, observing the same polarity.
  

Hope this helps.