I've got an AM reciever made from scratch.... as in the tuning coil is wrapped on a tp tube, all the caps are handmade with al foil and wax paper. Parts of cigarette packs were used. Rectification is an old razor blade. Only manufactured parts were wire and the carbon speaker from a telephone handset.
It's all doable... heck, someone did it first, a long time ago. You just need time, patience, and a severe lack of personal life.
/johnny