I will offer a few additional suggestions.
The '74 probably had a ballast ignition system like my '72. You need to convert away from that to use your new coil and at the same time provide full 12V system voltage to the Ignitor module. The test to see what you have is easy.
Run a jumper wire from the coil (-) terminal to ground.
Turn the ignition key to the run position. Do not try to start the engine.
Use your multimeter to measure the voltage between coil (+) and ground.
Turn the switch off and remove the jumper wire after making the voltage measurements.
The jumper wire insures the coil has a path for current to go to ground. This is a must for making coil supply voltage measurements.
If you measure 6V to 9V on the coil (+) terminal your car has a ballast resistor somewhere in series with coil power. You will need to run a new, switched, un-fused supply wire to coil (+).
If you measure no volts (0V) this says the coil is getting no power at all and you have a problem to sort. There is no substitute for a wiring diagram and the multimeter to sort this out.
If you measure 12V, then the coil is getting the correct supply voltage and the no-spark issue lies elsewhere. (Plug wires, plugs, cap, rotor...)
Let us know what you find in these tests and we'll help you troubleshoot. Don't forget to remove the jumper wire from coil (-) to ground when you are through making these test.
ALSO... since you are having no luck getting a spark, leave other wires OFF the coil for now. As an example, if your car has an electronic tach (likely since you have the 25D distributor installed), disconnect its sense wire from coil (-). Failed tachometers can act like a kill switch.
There is nothing wrong with the Ford solenoid. I have one on our GT6. If the solenoid works and the wiring has been set up for it... use the Ford part. They work well and are available at almost any parts store should you ever need to replace it. The square-ish Lucas solenoids are OK but they cost more and are not as readily available.
EDIT: You were typing while I was typing so I'll add more comments. How do you know the solenoid is bad? The quick tests are to put the gearbox in neutral and open the bonnet. Locate the white/red wire on the solenoid. Take a short jumper wire and hold it to that terminal on the solenoid. Take the other end of the jumper wire and touch it to the solenoid terminal with all the brown wires on it. If the solenoid is OK, there will be a modest spark (don't let that spook you) and there will be an audible click followed by the starter motor turning over. If there is no "click" make sure the solenoid's mounting foot has a good ground connection. Run a new, dedicated ground wire to it if necessary. Repeat the test. If there is still no click it is reasonable to say the solenoid is bad. If there is a click and the starter does not spin, that could be the starter motor or the power contacts in the solenoid. To test if it is the power contacts, take an old pair of insulated handle pliers. Rest one jaw of the pliers on the terminal with all the brown wires. While holding the pliers in place on that terminal, rotate them so the other jaw of the pliers touches the other large threaded post terminal with the cable going to the starter motor. There may be a BIG spark. Again, don't let it spook you. If there is no spark then something is amiss with the starter motor or its cable to the solenoid. If there is a big spark and the starter motor spins up, that says there is a problem with the power contacts in the solenoid.