40 manufacture of sealing and combustion components and assemblies to the order and/or specification of others; machine shop services, namely, machining parts for others; precision metal fabrication, namely, punching, forming, and finishing services; prototype fabrication of new sealing and combustion components and assemblies to the order and/or specification of others; welding services; cutting of sealing and combustion components and assemblies; finishing and coating of sealing and combustion components and assemblies; blasting services, namely, sand blasting, glass bead blasting, and grit blasting services