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.
Here's the base that I had 3d printed in steel:
https://photos.app.goo.gl/VCZ71WwMhDDUp4Eu5
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.
https://photos.app.goo.gl/BTF3irERL4MqU9F8A
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.
https://photos.app.goo.gl/LxUohmAGebpEcPLY7
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.