I can see their reason behind their current marketing products. The 3rd Gen grips they offer now fit a lot more models than the grips for the 3913. As far as I know, the 3913 grips are only interchangeable with the 3913TSW, 3914, and 908. The 5906 grips are interchangeable with: 5906TSW, 5904, 5903, 5903TSW, 5946, 5943, 4006, 4006TSW, 4003, 4003TSW, 4046, 410, 410S, 411, 910, 910S, 915. Making grips to fit 18 models, as opposed to 4 makes a lot of sense. What I don't understand is why they haven't made a set for the full-size 45's and 10mm's, as they are based on the same frame similar to how the full-size 9mm's and 40's. This would give them a market of: 4505, 4506, 4546, 4566, 4566TSW, 4563, 4563TSW, 4567, 4586, 1006, 1046, 1066, 1086. Plus the 4563TSW and 4566TSW, are still in production for Law Enforcement.

*I know I probably missed a few interchangeable models.