Good. I was concerned that you were discouraged. I don't like it when parents and kids have doubts and fears artificially inserted into their minds that otherwise wouldn't have been there had they not taken the great and responsible initiative to learn how to better their craft. Besides the fact that most people who plant them in your head have some agenda of their own (bragging rights or a product to sell for example), I know first hand that all of the "noise" of information gathering weirdly can blur your own reality. By taking a step back, you will better be able to see the obvious again, which is:
Whatever speed your son is throwing right now must be fast enough.
After all, he Ks a lot of batters, right? They're not roping dingers over the fence off of him every outing, right? He seems to be a go-to guy for his team, right? Bottom line is, he gets the job done in the venues/competition level he plays in right now, right?
Welll, a pragmatic approach (something most of us baseball parents struggle to take !) suggests that might just be all that you REALLY need to know about his velocity for now. After all, no radar gun is needed to confirm what you (and, more importantly, his opponents!) see happening when he's on the mound....no more than anyone needs a tape measure to figure out who the tallest people in the room are.
At least that's how I have always tried to see it, or at least that is approach has been what worked for us. Right or wrong, if nothing else...it has allowed us to exhale and enjoy the ride, something I wish more parents and kids in youth baseball could do, too.
Best of luck-tell that boy of yours he's got some folks in Indiana rooting for him