I was told by my vet that a pup at about 6 months should be weaned down to about 3/4 times a day of feeding. However, having said that, with your baby being so small, I would probably free feed and have kibble available to him at all times. Hot Rod was small like Toby and it took forever for him to get to 2 lbs! He had access to food all the time. Now he's a solid 5 lbs.
Toby is a cutie pie.