I didn't even own a welder when I built the first 5 straight axles cars, and never dreamed of using a custom newly built axle kit then! I figured out how to make mounts for those straight axles that I could bolt to the factory frames, and then went to friend's garages and used their welding bench to fabricate bolt in front axle perches.
Some of it improved with each car, as I learned about things like kingpin angles, and improved the handling charachteristics. The first '57 I did was pretty ill handling at high speeds above 80 mph. I also improved the mounts to make them cleaner, and still bolt on the frames and be easy to install. I thought back then that I'd even pursue fabbing up kits to use the plentiful '55-'59 Chevy truck axles, but they seemed to be getting harder to find even then, and I saw not future in it.
When I look at the resources for tools I have now, (and they're not a lot!) I would have been in heaven back then to be able to do those axle installs!