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This is something that the community might find interesting - After getting a Leupold Deltapoint Micro for a Glock on a pretty killer sale, I decided to make a mount for my (old style) K40 carry pistol, since I couldn't find any good MRO options that didn't require machining the slide. I had to do a couple of iterations to get the dimensions right, but I think it turned out to be quite serviceable, and doesn't require any permanent alterations to the gun, and the only tools required are a cheap M4 drill and tap.
Here's the base that I had 3d printed in steel:
Since you really can't effectively print good M4 threaded holes, I clearance drilled and tapped them to fit the screws for the DPM. The base was a good press fit to the slide dovetail.
The DPM mounted up just fine, fits nice and securely, though you have to take off the battery cover to put the slide back on the frame.
If anyone is interested, I'm willing to share the 3d model file for a nominal donation to offset the development costs. I had the piece printed by Shapeways, which cost about $40 including shipping, to have it printed in steel.