Could an ordinary man of common skill, and mundane origins create fully functional androids (mechanical humanoids), because he wished to have a family of his own in despair and desperation? It would definitely take decades or all his lifespan, since he's not like some protagonist in a fiction or a born genius in science. I mean, what are the least chances of that happening in the right conditions in his lifetime? Can he truly create an artificial soul and die comfortably knowing at least his own creations loved him (out of free will)?
At that point I think it would really depend on the setting. If he lives in a world where even the most common of men could build an android that of course it will be possible. But let's say that he during the cusp of technological advancement, where only those with skills, money and expertise have access to both knowledge and resources, then I don't think his dream will be plausible. Developing technology is pricey.
Depends on how far he is willing to go , as you said he Is a common man but such a project would need a lot of resources which obviously he won't be able to obtain being white . If he is willing to go down the dark path and do everything he needs whether right or wrong to attain his goal then there is a chance he might be able to do it. Like it or not a common man with very average talents needs to get his hands dirty if he wants to do something very extraordinary.
If he has no family, he'd have plenty of money to work with. I think it's doable in the modern age, as long as someone devotes all their life for it.
Ordinary as compared to what timeline? Past, Present? No, I don't believe so. Future? Probably. Depends on the available tech.