Can you not download a base map for the car to get it up and running ?
What engine ? What spec ?
My first thought would be to take it to Northampton Motorsport, they map cars almost daily on their rollers and have experience with a range of ECU's Weber Alpha, Omex, Jems, etc
And they have done a few cars with Megasquirt fitted, mainly Westfields with Zetecs etc
But they know their onions
www.northamptonmotorsport.com
01604 - 766624