What can you manufacture at home?
Anything diecast would be very difficult considering the tools and equipment you would need, but I know many people that use sheetmetal to fabricate truck models, constuction equipment models etc. You would obviously have to have the skills and training and the equipment, but it is somewhat like carpentry, only with metal and soldering instead of wood and nails. You could also make toys out of wood and there are many people that do that. That ranges from simple childrens toys to more complex games, puzzles etc.