Is My New Aussie Crossed Or Under Weight?

by Shaunna
(BC, Canada)

I am new to the Aussie breed. I rescued this little guy and have named him Scooter. Because he is a rescue, I am unsure of his background. The vet said that he is an Australian Shepherd. I'm wondering if you Aussie experts think he is crossed with another breed? If so, what breed? I'm also wondering about his weight. He is 8 weeks old and only 3 lbs. The vet said that he is on the small side, likely because his mother was malnourished so he didn't get the proper nutrition from her. She seems to think that he should bounce back fine and end up between 25-40 lbs. What do you all think? Thanks for your help! I appreciate it :O)