The "magnet" evidence you have presented is consistent with the shell being Aluminum (Ludalloy) or Brass. All it means is that the shell is not made of a ferrous material like Steel. There are definitive tests based on weight (plus a few destructive tests which you probably don't want to use). And is there a seam where it was welded? I might be seeing such a thing in one photo.

I don't see the sort of snare beds (called crimped) I'd expect on a Brass shell. But I'm no expert. And anything is possible with Ludwig.

There is a l-o-n-g thread on this in the general section

http://www.vintagedrumforum.com/showthread.php?t=9441

and there is a video about telling them apart on YouTube (most entertaining)

[ame]http://www.youtube.com/watch?v=ajWv4NoQQac[/ame]

If it is Brass then it is worth a lot more than if it is Ludalloy. If it is a Ludalloy it may still get a price premium if it is all original and doesn't have any pitting or tarnishing on the shell. Brass shells usually don't get pitting, but Ludalloy shells do suffer from the chrome layer pitting and starting to get "acne".

I don't know the current range for Brass snares of that vintage, but I would expect well over $800 on eBay. I don't track the prices carefully. The Ludalloy ones go for $200 to $500 depending on how pristine they are. The amount of variation in price is quite high so you really need to track lots of them to completion on eBay to get a good handle on the amount of variation in price. Otherwise people just tend to remember a few unusually high values (because they are memorable) and quote those as if they tell the whole price story. But then I am a statistician... :o