This replica of a Mamiya NC1000 P-Mount adapter for M42 lenses is fully functional and will save you the trouble of searching ebay for years, trying to find the rare original Mamiya P-mount. I used an original p-mount that I own to measure and verify accuracy when designing this replica. Rest assured this item works great in any NC1000 or NC1000s camera.. (tested using a Mamiya M42 50mm f/2 lens)
This design is fully functional but upon receiving the part you must use a hobby knife to release the moving part from the non-moving bits in order for the aperture to function properly. Doing so requires a simple 4mm slice to release 2 parts that get loosely fused in the laser sintering (3d printing) process.
Here is a HOW-TO video demonstrating the hobby knife procedure: http://www.polymetric.net/pmount.mp4