Well, it's good to know he is normal!!
I posted pics of him in the photo section,

I am pretty sure he is purebred!
Our Magic, is only about 11 lbs..she is a little thing..but she is a boston/?? mix
I just assumed he was big for a boston, because I have only seen the smaller ones, my aunt's purebred boston (magic's mom) was only about 22 lbs, so she wasn't as big as buddy.