I sent my IWB back to Blade-Tech to have them retrofit it with the J-hooks. In just a few days, they returned my old holster with a note saying that it was an earlier style that did not lend itself to the retrofit along with a new, current-production IWB with the J-hook belt attachment. All they charged me for was the cost of the J-hook I had requested ($7.95). Once again, Blade-Tech has shown exceptional customer service!
The new holster works nicely. It has cleaner "lines" than the early holster and the attachment mode for the J-hooks (or straps) is cleaner and results in a thinner profile.
Speaking of J-hooks, I recently saw an ad wherein Galco is offering a J-hook belt interface on some of their IWB holsters. One thing about Galco, if they see something desireable on the market, they waste no time in "appropriating" that feature for their product line.