I've done a couple. I wouldn't attempt without a router table and a drill press. A router table with a corebox bit and a few straight bits will take care of the lions share of the inletting. Corebox bits are avalible by 1/8" increments that will get you close to the receiver dia. Unfortunately only close due to the metric tubing. A drill press and a few forstner bits will handle the trigger assy. Complete all the inletting first before messing with the outside. After that it's just a matter of removing all the wood that isn't part of the stock :>)
Depending on the type of maple it may not be a good choice,some maple is soft.If you go with it,when you cut the thickness of the blank cut at least 3/8"thicker than needed do to the wood shrinking as it dries.Also slop some paint on the end grain of fresh cut logs to help stop splitting.Air dried lumber needs about one year per inch of thickness.Good Luck let us know how it goes ,hope this helps
Gary