I have begun making adapters for S&W K frame square butt models. Announcement is here BK Grip Adapters - Square Butt K Frame prototypers wanted, looking for initial prototypers who will see if the same adapter works on N frame models (it does on my 1917, but may not on others - we'll see.)

I will post a new classified ad when I know if I can describe the item as suitable (or not) for N frames as well as square K frames. Meantime, those who are interested can look at the above thread for feedback from early users.