What level of work expected NDD?
Comprehensive work or just a field kit?
The MOAKS item is indispensable imo if you are dealing with other people's guns that are not Colt / milspec mfg.
http://www.m-guns.com/tools.php
Mother Of All Carrier Key Stakers (MOACKS)
Pricey but worth it and a lifetime tool. Easy to use and stakes the screws properly.
Of course ... the Journeyman Lineman in me is screaming you could just beat on it with a hammer and a chisel.