Nobody here can tell you whether he's gifted, in what ways, or how much. Also, the Ruf levels have some issues even when applied to older children (tied directly to IQ scores, which AFAIK aren't directly correlated to milestones, but essentially heavily tied to milestones as well; disregarding the cases of late-milestone gifted children; vague, sometimes contradictory criteria; small sample size; etc.). Your son sounds like he's definitely got some early milestones, which can be an indicator, but there's actually not a way for anyone here to give a hard prediction based on them whether he's gifted. If I had to take a wild guess, yep, he's probably gifted to some extent.
You can get testing done using an early-age IQ test like the DAS-II (2.5 years and up) or SB5 (2 years and up), but the numbers you get will probably be highly unreliable-- they'll help tell you where your child is compared to others of the same age, in terms of rareness, but the results will probably be highly influenced by the amount of richness of your child's environment, more so than for older kids. I read all the time that numbers can be quite skewed even for kids 4-5 years old, depending on how much they've been stimulated to learn at home (even quite regular exposure to some PBS programs could IMO put many children ahead in recognizing letters, shapes, etc., or similarly the Leap Frog toys you mentioned).
What I would do is just keep him happy, playing and learning, which all children should naturally be naturally doing at that age. Whatever you're doing is working for your particular child, so keep it up!
