The box is on the way to
@finsruskw.
I think I've solved why there have been so many problems with the Rivnuts (and similar). When I removed the cover screws, one of them required enough torque that I was concerned the nut might fail. The nut survived, however I noticed that the threads were damaged near the end of the screw . . . . Eureka. The screws I removed were mixed lengths, some 1/2", some 5/8". Both screw lengths, when the cover is installed, extended well beyond the end of the nuts (various types now). That projection, beyond the nut, makes them vulnerable to damage from the contents of the box, as well as potentially doing damage to contents. I bought 3/8" long screws, put some in the "spares" package and installed the cover with same. I think the 3/8" long screws have adequate engagement for this application and they should be exempt from being damaged by the contents of the box. Slightly less than what I call snug is plenty tight enough for the cover screws.
Below is what I took out.
Left to right, top to bottom:
Pinion shaft, 24 T, 24 DP, 14° PA, 3ea SPG 634, Gr. K42 Inserts, 1ea SPG 633, Gr. T5 (Cobalt HSS) Insert
5ea TPEE 731, Gr VC8 Inserts
ER20 1/8" collet and ER20 Nut, 4ea 1/16" hex keys, 3/4" sq. HSS tool bit, 1/2" x 2" annular cutter, 2ea 1/4" brass laps, 2ea 5/16" brass laps, 7/16" x 3/16" power bit, 7/16" x 1/2" power bit, 1/4" x 5/8" LOC x 3/8" shank 3 flute roughing end mill, 5ea assorted Letter drills, 1/2" stub drill
6" Bastard half round file
8" double ended tri-square file
6" double ended tri-square file