Dave,
I do not know about earlier years, but my 54 and later flywheels had a spring-material molded-metal plate between pairs of bolts. These did not have bend-over tangs. There was a cupped surface in the plate that was directed towards the center. There were no lock washers and the heads are quite thin, as described by Denny.
As you suggested, I have always just torqued the bolts with the metal plates in place, and I have never had any problems (but I have had bad dreams about those bolts, and, bolts and tangs on enclosed driveshaft u-joints coming loose).
Next time, I will sleep better by using a version loctite that is made for removable bolts (even though it is probably unnecessary).
Tim
