was that me? I made mine in one night. I am impatient. Someone had asked me to make them a pair sometime last year...just way to busy with home and work back then and nothing has changed.
if you are handy, have a few pair of 3913 grips, a hogue grip adapter, some sandpaper, dremel...they can be made.
if you notice, the grip is hard to square on the frame since the frame on this value line and actual 3900 frames are different in the frame where your hand webbing rides.
the mainspring is held by the hogue grip adapter, so no worries there. Your grip is not going anywhere since your hand grips it and held on by a pin or if you are really good and patient, screw to the hogue adapter.
I think it would require some manipulation in the webbing area of the grip for it to square up and the cut out of the mag release assembly to line up with that portion of the frame.
I decided to just enlarge the cutout on the grip but in my opinion, as long as your side plate is completely covered by your grip, you are ok.