Before I got into all that machine work I'd hunt down a set of disc brake Dayton axles. They exist, I've seen several.
The rear would be a pretty simple swap, might gain you a more favorable gear ratio if desired.
Front might can swap entire axle depending on over all width and the spring center measurement. Or could possibly keep original axle beam and simply install or slightly adapt spindles to the old axle, hubs and brakes follow after spindle are fit.
I have not read of anyone adapting and machining and making disc fit in place of drums on Dayton axles, probably the difficult way to go if even possible.
Grigg
