Stick with the new job is there is room to move up you'll get same money within no time if things are as you say. Plus the added experience and set-up / design / programming know how will pay off for you in satisfaction and self confidence. Are you running swiss machines / screw machines or high speed cnc small parts turning machines ? At middle age we need challenges like this to keep us moving forward. We just bought our first turning center 2 years ago, Mazak QT8N with T+ love it.
Love how being out of 'the truth' enables me to focus on my shop and personal growth. Fellow JW's would look at any and every opportunity to belittle me on my 'secular' career and tell me you work to life not live to work. Yeah right..