When Captain America throws his mighty shield

The title is the opening line from the lyrics of Captain America’s 1960s cartoon (followed up by “all of those who chose to oppose his shield must yield.”). If you didn’t see it, count yourself lucky; the the animation quality makes Hanna-Barbera look like Miyazaki.
While I didn’t have time to catch the Captain America movie this weekend (or even confirm that it’s out), I figured it was a good time to discuss somethign my rereading of Silver Age comics has made me aware of: Cap’s mighty shield didn’t use to be all that mighty. As with Batman, Cap’s shield has been upgraded a lot since the Silver Age.
In the 1980s, the Shield was described as a vibranium/adamantium alloy; one story asserted its molecular structure was even tougher than the Silver Surfer’s surfboard. Some years later (apparently after it occurred to some of the writers that adamantium didn’t exist when Cap got his shield) it was retconned as a completely unique alloy—adamantium was a failed attempt to duplicate the original.
Browsing Essential Avengers Volume 2 and the first Essential Captain America, it was a real surprise to discover Marvel treating the shield as a nothing but a fine piece of metallurgy: Perfect aerodynamic design for throwing, but that was about it.
In Avengers #35, the Living Laser’s deathtrap disintegrates the shield; Cap refers to a special alloy coating that the Laser’s earlier blasts burned away. We later see Cap run into battle with another shield, so presumably he had spares.
In #44, the Red Guardian damages the shield (by his belt-buckle, which is designed as a miniature shield-equivalent throwing weapon) so that it doesn’t return to Cap at the end of its throw.
The shield was considered unremarkable enough that Lee and Kirby decided to jazz it up by having Tony Stark install remote-control gadgets that could make it really fly (they wisely dropped that idea later). When the Plotter tries to steal the shield (Tales of Suspense #87) it’s for the remote-control tech, not because the shield itself is anything special.
The first time it was treated as something special in its own right was Cap’s first encounter with Modok (TOS #93 and #94—I’m not sure which issue) in which the mutant brain’s hench-scientists discovers the shield is completely indestructible, even in the face of ray blasts and diamond drills (they speculate it’s extraterrestrial in origin—I’ve no idea of Lee and Kirby really intended that to be fact or not).
But like Batman and Superman (and Cap himself), the shield has to keep pace with a world in which the Silver Age power level is old hat. So it’s now unique and more indestructible than indestructible. Even if it’s currently in the hands of Cap’s No-He’s-Really-Dead-And-Will-Never-Ever-Return-Oops-Guess-He-Did partner Bucky.
So now you know. For whatever it’s worth.
(My thanks to Mike’s Amazing World of Marvel Comics, without which I wouldn’t have been able to pinpoint the TOS issue numbers).