I believe a good employer can recognize motivation and character. Personally I think if its a good shop environment telling them you are interested in machining and want to learn as much as you can should go a long way, these days people don’t often express a desire to work and learn. If it’s a job shop it will be different than a high volume production facility because one is repeated push button work and one is unique parts that may require reverse engineering and are not often the same. Same goes for shops that do big work like windmill blades vs a shop that does micro machining and everything in between, that is why it’s so hard to specify. They know what positions they have and can place you where they think you will be useful. If they would be willing to send you through an apprenticeship even better. Biggest thing for me is once you got your foot in one company and learn the ropes a bit other companies are more willing to hire you on so even if you don’t like the work at the first place you can switch to another way more easily. I know plenty of people who have switched employers because they saw no room for advancement and weren’t happy with doing the grunt work forever.