Do they need to be disclosed?
Most of us can come up with an educated guess what the business looks like based on the equipment, the in-a-garage location, no mention of employees and no tales of woe about weird expensive materials. Ballpark, material will be between 25% and 50%, tooling will be maybe 10%, electricity 10kW at $.15 or so, upkeep and fluids and compressed air and misc another 10%. We're mostly owners here and we all have at least minimally similar businesses. We can infer. So his expenses are almost certainly in the 40-60% range, which leaves $70-100k a year pretax coming off of one machine in a garage. That's... really not bad. It's a comfortable middle class living.
If the only answer the OP is looking for is "can a turning shop in a garage make a go of it" then that is one data point in favor of "yes, yes it can."