It's refreshing to see your honest assessment of his abilities. You mention that his velocity is low, which it is even for a lefty (unless he is a sidearmer, submariner or similar pitcher). How did he pitch this past Spring? Was he effective on the mound?
We were in a somewhat similar situation when my son was a Senior. Although he had very effective Junior and Senior years (low eras, low hits against), he was not looked at by D1 colleges. He wanted to stay within 5 hours and there wasn't a D3 or even a D2 that had either good enough academics or his major that also wanted him to play ball within that distance. He was offered some nice scholarships by D3 schools for his excellent academics yet they were still well above what we'd pay for an in-state public university. A month before he graduated he made the tough decision to go to the academic school(a D1) that he wanted and play club ball there. Adults in his life (coaches, etc.) told him it was an admirable decision. His teammates told him he was nuts not to play "real" college ball.
Well, he had a different ending than most in that he was recruited by a D1 AFTER he graduated and after he'd made that tough decision. Fortunately for him, the D1 that wanted him was also in his top 3 for academics, etc. It was a crazy month of transferring records, unregistering and registering and notifying his roommate. Fast forward three years and he was their go-to pitcher out of the bullpen this year and even pitched in a Perfect Game Summer League All Star Game (a seven pitch inning!).
I mention his success, because if he had NOT been recruited late by the D1 he would have never known that he could be that successful. He has told us that looking back, he should have focused on going to a JUCO and then transferring into an academic school once he proved himself. If he didn't prove himself nothing would have been lost as he'd have gotten his core classes out of the way.
Someone else might know better than I, but I believe D3's and JUCOs often recruit much later than D1's. Spring and even Summer after graduation? Can he go to their camps and hold his decision until next Spring? He can do as my son did and apply for his academic school and then once he gets accepted, they usually have until April/May of their Senior year before they decide. Now this means that if he is liked by a D3 they will call him weekly which can get tiring.
If toward the end of his Senior year it's evident that he has little chance to play at a school that has the academics, finances, etc., then club ball is an EXCELLENT choice. Most get uniforms, and travel all while having a less rigorous schedule and being able to take advantage of other school options like going on exchange, etc.