Excellent paint job! Putty worms have been my method of choice for years for doing complex soft-edge camo.
If you don't mind, I'd like to share the "sophisticated" putty-rolling tool I developed for this purpose. It makes rolling thin, consistent diameter worms a cinch. It's simply a smooth ceramic wall tile, available at any home improvement store, and a scrap of clear acrylic sheet. Simply place a ball of putty on the tile and roll with the acrylic sheet. The latter being clear lets you easily see the results.
Cheers,
Eric