That's a tough one. I'd guess that given his age and grade that he's on the older end for grade. Is that correct? If so, I'd want to see the achievement piece be beyond the minimum for DYS, which his EXPLORE is.
I might, in your place, consider applying with the portfolio and what you have, but if the portfolio really isn't something you want or can pull together and you can pay for new IQ testing, I guess that I'd re-test IQ and see how it comes out before applying.
We've never applied for our one dd with DYS eligible IQ scores b/c she is 2e and doesn't have supporting achievement and getting a ltr of recommendation for her would be hard b/c she is such a chameleon, so take my suggestions with a grain of salt b/c I have no personal experience with applying.
