Hi, Nice work.
I have a few questions and some remarks.
Why did you decide on mahogany for the body? (I'm not much of a woodworker and dont know availability and stuff) Strats are usually Alder or Ash if I'm not mistaken. The body wood has a small effect on the sound but importantly, it makes a massive difference in weight. Don't want the guitar to be too heavy. Les Paul style guitars are solid mahogany and are notoriously heavy.
I don't see the truss rod cover on the headstock end of the neck. Did you put the truss rod's nut at the body-end? If you did, make sure to leave enough space or make a tool that can reach it without the need for taking the neck off to adjust the truss rod. If you didn't install a trussrod then well, you'll have to, steel strings put quite a lot of tension on the neck and will bend it out of whack if there isn't a truss rod to counter that tension. This is very important for the setup of the guitar.
What kind of finish where you thinking of putting on the mahogany? Will it be stained first then clearcoated?
Regarding the guitars for your son and the one you're planning to sell. My advice would be to make them as plain and standard-looking as possible w.r.t. styling e.g. no markings or lettering on the front of the body and white or black dot inlays on the fretboard and a the body would do well with a mild stain and a very thin clear coating (not varnish). Since you've used mahogany for the body the obvious guitar to look at for finish would be a Gibson SG:
