see good egg.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
Examples from the Web for good scout
Johnnie, with the water dripping from his yellow hair, was no longer in that generous, good-scout state of mind.The Rich Little Poor Boy