Suggestions

Deletion program - produce components locally. Import duty free under condition that 75% will be produced locally. First gummit allows import of certain parts, then the company starts to produce.
Generator business - lots of big guys, but it's easy
Solar power - everyone is cheating, say 100MW plant. Efficiency goes down, say to 3 MW - solar tracking. Efficiency level is fluctuating. That is difficult. Washing panels, etc. Even the germans say you will get 30% less. So cost of project is wrong. Should say, it's a 100MW, but you only get 60MW.
Mobin developed 250 machines
Ex. Movin offered $10k for a machine that cost is $100k. So they were getting the machine for $50k, and $50k kickback.
Ex. a spinning mill that requires 12,000 spindles. $10M project. The company pays $1M.

Engines

Engine head and block - casting - machining schould be easy, casting should be low cost. Cylinder head and block. One cylinder, 2 cylinder, 3 cylinder diesels. Marine engines are modular - you stack on additional sections to get more power.
crank, cam - no problem
Modular engine - yes!