I was curious what the material on American Vintage '62 ReIssue Strats the tremolo blocks are made of. I noticed a magnet sticks to mine, but have read, perhaps fallaciously, that they are zinc, even on American Vintage model Strats.

Thanks in advance.

To clarify: I'm curious on the authenticity of my instrument. Does Fender normally use steel trem blocks on AVRI 62 Strats?

I have a '62 Hot Rod and a magnet sticks to mine but I really don't think it's all steel.
This is considered sacreligious by some but I replaced the bridge and trem block with a Callaham's just to see what the hype was all about and really,it did improve the tone....is it worth it?...if I was struggling to come up with the money,no...it's not that big an improvement to a guitar that already sounds great.
But tone chaser that I am,I had to try and it sounds good....good enough that it's staying in the Strat.

The trem block on an AV Strat is steel. I think that Callaham is trying to use the exact same formula steel that Fender used in the 1950s while Fender is using a modern equivalent (but slightly different) formula.

The zinc alloy blocks were used on American Standards/American Series up until the introduction of the "new" American Standards in 2008. I'm not sure about the vintage-style bridges used on MIM Strats, Highway 1 Strats, etc.