[gary rabbitt]

What should I measure with the voltmeter?

At this point, I haven't found anything newly connecting, or wrong parts placement. I've ran the tests described in Riders volume 19, p.73. - It points to bad capacitors, do I start changing capacitors until I have AM reception back, or should I try to get AM back prior to making replacements, in order to be able to test any upcoming capacitor change.

Hi,
I would suggest that you do not replace anything further until you solve your problem. The reasoning is, it did work before you installed the filter caps right? Now it doesn't. Starting to replace "other caps" will open a large can of worms, and probably won't get your set going. You will be deeper in trouble if you miswired one of next caps.

So, I'd start making the voltage measurements, usually from the chassis (check the diagram) or a common B- point.
A visual check might turn something up. I have checked a chassis once, twice and 3 times. The 4th time I noticed where the trouble was. So get out the highlighter and make 100% sure your new filters are in correct. You did add the terminal strips, perhaps you forgot to route a wire that was going to another stage? Something grounded where it shouldn't be? Maybe snag a thin wire somewhere? Hard to diagnose here.

With the voltages checked, you can go from there. Remember, some of your voltages might read a little high due to the higher AC voltage in some locations.
Will check back