Here is a great place to start:
https://antiqueradio.org/recap.htm
There are TWO very different capacitors in this radio. A aluminum can mounted up top that has 4 capacitors inside. The values and voltages are marked on the side of the can and has symbols to indicate what lug underneath is what. It is VERY important that these are wired in the right polarity. Chassis is negative and the leads that go to each lug of the can are positives. If you look at the images and see the new brown caps, those replaces the 4 values of the aluminum can. The rest of the caps are NOT polarized and can go in either way. The most important cap goes to the transformer inside a metal shielded box. Remove the top and you'll see it. Its something like a .003 Microfarad cap at 1600 volts DC. That thing gets beat to death.
Here is a link to decoding the bumblebee caps:
https://pickguardian.com/wp-content/uploads/2014/04/Sprague-Bumblebee-Chart.pdf
As far as aux cord to the radio the set has a dual stacked pot, which is the volume and tone control. Each of those will have three leads: A top, bottom, and a center lead. Ignore the center lead. These come right off the volume control itself ( the thing that the volume knob is attached to ) I ran a 3.5mm stereo cable into the set with a 3.5 mm male at the end. Take the right and left channels and run each side to a 30 ohm, 1/4 watt resistor. Then tie the two resistor leads the other end together. That will mix R an L channels together safely. Then that will go to the positive side of the volume control. Its the side where the radio signal comes in. You can test with some clip leads first.
I'll try and post better pics later.