If you can set aside about £ 3000-4000 and have a spare area for a workshop then buy him some second hand lathe like Mayford ML7 or Super7, together wih accessories like vertical slide.
You will find plenty on offer on ebay and elsewhere.
Consult someone experienced (ask him to inspect this lathe before you purchase) and ask him to set it on.
Plenty of knowledge can be found on internet (and your son will find it easy) but before he has made his first steam engine it will likely be few years of skill learning.
He must be *patient*.
Amateur engineering / precision mechanics requires lots of *patience*.
We are often spending many days to fabricate a single part.
This hobby is not cheap either and your son will unlikely make any money out of it unless he has acquired some very special skills or found a niche or unless current edition of civilization together with high volume manufacturing have collapsed.
West is essentially done – even multimillion engineering ventures are struggling and increasingly failing while competing wih Chinese.
Edited By Martin Dowing on 14/02/2021 21:36:53