Update: Combined the individual models and added captive nuts for all the mounts.
I haven't printed and tested this yet, but based off of the freely available drawings I found around the web, this is what I came up with.
This should be completely bolt on, usable with the stock lead screws. I would suggest that you purchase real couplers and spacers instead of using 3d printed. The only mount that would not bolt onto the machine is the X Motor Mount V2. This mount would require drilling and tapping two holes. I included it because I saw many conversions use this method and it's a much smaller piece that would need printed.
I plan to print this to test and to use in the short term before doing a full conversion with ballscrews and aluminum mounts.
I'd print them as strong as you can.