HI,
Excellent Job!!! Save me a ton of time.
One small comment, I think that the text for pins 50, 51, 52 & 53 should be moved up one row.
The bottom row of the MEGA is for the ground connection.
Again, thanks for all you hard work. I really enjoy working with ExpressPCB, and their boards are very good quality. Finding files like your are real help.
Thanks & Happy New Yera