I used Granada spindles and calipers on my 73 with a 74 Maverick manual disc/drum master cylinder. Works good but there are some kits available now that allow the use of the drum spindle.
Its best if you can buy a good parts car for cheap. I took the 5 lug power discs off this 75 Maverick 4 door big 6 car i got for $300: and swapped it all on this 70 Maverick, 2 door, 4 lug, 4 wheel manual drum, small 6 car I am building: it was 99% bolt-off and bolt-on. I had to drill one 1" hole in the firewall for the plunger rod to pass through in a different spot. The same can be done with 71-77 Mercury Comet, any years of Ford Maverick Granada and Lincoln Versailles parts. The Lincoln Versailles and some rare Granadas had 9" rears with disc brakes and are highly sought after for Maverick/Comet builders. Other models of Ford Mercury and Lincoln cars have some parts that fit here and there, but it really depends on how hard you try to "make" it work. Just for example; Fox body Mustangs and Thunderbird/Cougars offer very little to us as parts mules.
