I had less than 400 hours total time as a pilot, but I had an A&P and a Flight Engineer ticket. My company has a minimum to upgrade Engineers with 900 total time, 500 hours on the company's panel, and 2 years total with the company. My previous company would upgrade Engineers any time the wind changed direction and the Engineer being upgraded had a Multi-Commercial, Instrument, and a First Class Medical. There were quite a few 300 hour 727 First Officers flying after they rode the panel for a year or 2. I will be eligible to upgrade with my present company in a little over a year, seniority willing.
One thing about Engineers........I'm the 5th Engineer from the bottom, but once I upgrade, I'll be senior to almost half of the FO's. The reason for that is the Engineers don't move up quickly.....and there are a lot of ROPEs......Retired Old Pilot Engineers, just hanging around. I don't mind it though, That's what seniority is all about. One day I will have it, and by God I'm going to appreciate it.