For what you will have to spend to acquire the components to complete the rifle, you will be better served taking the time to find and buy a complete M1D. The Field Grade M1Ds are definitely graded correctly and not undergraded.
If you go the CMP route, plan on spending approximately another $1000 obtaining the rest of the components... beware of inexpensive M84 scopes... they are inexpensive for a reason... internal rust, paint flaking off the inside of the tube, rendering the scope difficult to use. A really nice M84 will run in the $500-700 range. M2 flash hiders are getting expensive also.