Joe, as Sharon has described, I have done the same thing for my seamstress wife. She has educated me on what most seamstresses and quilters need and use. As to the small size like Sharon quoted, your precise bore hole in your handle will either allow the user to reverse the ripper to "park" the blade, or sit the ripper handle to the notched spot at the halfway point of the handle, and use the clear plastic cover that comes with the ripper. The problem is that most folks want to get away from depending on the cover, because they can get lost.
The other thing is that sometimes there is a demand for the larger ripper blade. This one comes with a rectangular plastic handle. I remove the blade unit from the handle, and insert it into a matching small hole in the turned handle with a dab of epoxy. For a cover, I turn a matching material cover to sit on the nib end of the turned handle. Admittedly, this method would require the user to hone the blade with the small rattail diamond file, or have to forcibly pull out the old blade, and repeat the process of cannibalizing another store-bought unit to install a replacement blade.
I apologize for the long narrative, but I have made and given/sold several of these units to happy users.