Suggest:
Increase salary by 60% per hour and make all bennies fixed, for some term, like 3 years minimum independent of employment.
"Prototype machinists" are usually the most skilled, fastest, ingenious guys who make anything from anything, and often really well, and often really cool looking bitsies.
Every single big company in the world, from SpaceX to Boeing to BigCarCo wants all the best prototype machinists it can get.
And so does Amazon, and Google.
At 180.000$ per year, plus, according to glassdoor.
Any machinist can make prototypes, but "prototype machinists" are generally the best guys well rounded in manual and cnc and finishing and fixturing and automation and scaling up production.
The prototype machinists at tesla or say flextronics or say apple command well over 1M$/y compensation -- usually somewhat tied to stock grants so they don´t leave early.