That's the 1960-61 model.
Do you have a multimeter? First you should see if the elements are still good or not. They could be good and not heating because of bad wiring, bad connectors or bad thermostats..
Since they are the easiest to test, without pulling the wall oven from it's location, they can and should be tested first but don't presume they are bad just because they are not heating!
With the oven turned off, you just need to pull on the lower bake elements to disconnect them (don't try that with the top broil elements, they are not designed to be removed!), then with a multimeter set on the ohmmeter function, you can see if there is resistance (good) or if it's open or shorted (bad). The center connector is the safety ground and testing the conductivity between this connector and either of the two other connectors should show no current passing between these. Now, if you put the probes of the ohmmeter on each of the two exterior terminals, there should be some current passing through them. You should see a reading.
If you don't have a multimeter, usually, you can get a cheap one at various stores for $10-$20 and it's a useful tool for anyone!
If you're wondering how a Ohmmeter works, it's simply powered by a small battery that sends a small amount of current (nothing that can harm you!) through the circuit you test with it. Then it reads how much is lost in the circuit (the resistance).
Heating elements are made of a conductive material that doesn't conduct electricity too well. The resistance allows to produce heat (a lot of resistance means not a lot of heat and very low resistance means a lot of heat). With the low current sent by the ohmmeter, it doesn't produce any heat but when connected to a 240 volts circuit, something else happens!
The rest of the wiring and connectors need to be very good conductors, otherwise they'd also produce some heat when your oven is turned on and they're designed to handle some heat but at some point, they fail!
After years of use, some connectors and switches (like those in the thermostat) can become dirty and become resistive. When that happens, the heat can damage them to the point they aren't working anymore! So if the heating elements are fine, you need to look for bad connectors, burnt wires (often near the bad contact) and for a thermostat with burned contacts from the repetitive on/off cycle and dirt caused by the electrical arcing produced every time the thermostat cycles.
I didn't watch the whole video but this guy explains how to use an ohmmeter. It will probably help a bit if you aren't too familiar with using one!