Mercury Engineering — in 2018, the most profitable construction company in Ireland — have released a strong set of 2019 results.  Turnover is up 16 per cent, to 892 million. Gross and net margins are up. And the company made €40 million in net income. That’s up 36 per cent on last year.  Mercury isn’t highly levered. It has €122 million in net assets. Being a construction firm, its receivables and payables numbers are both huge. But it has €126 million of net current assets and only €9 million in long term debts. Interest payments are just €356,000. Mercury was…