All I could afford wrote:
I'm just curious how the original builder secured the tie rods in a theoretically perfectly straight ahead position. It seems like a lot of potential for play between worn tie rods, ball joints/kingpins. I'm no stranger to using the things I have around the yard to save money on a project, but if I was building a trailer, new axle, electric brakes or no brakes if light, and keep it light and simple.
Securing the spindles is not a big deal. I built a bike trailer on a Ford front axle. Got out the tape measure, a square and some string to get the spindles perpendicular to the axle. Set the toe in and welded the spindles to the axle. DIYers do it all the time.
Richard