This is a pretty good presentation on the history of this conversion. As you can see in the video this is probably the least machining intensive conversion.

Use of a BM59 trigger group would do away with the rear mag catch adapter.

The front mag well adapter is petty nice in that it finishes off the magazine opening nicely in the stock. Beyond that it can be simplified by a front mag release type used on the Santa Fe/FedOrd version.

Tim Shufflin has the M14 mag conversion down to a fine science and does it much simpler. Tim also has a bolt hold open that takes care of the issue in the vid.

The gas cylinder, in my opinion, eliminates the cutting of splines and threads which makes the conversion much easier along with not needing a gas lock/screw to retain the cylinder. The ported gas plug is about as simple as it gets.

interesting conversion.

https://www.youtube.com/watch?v=4fjYaSaiUZo