Well, there's about 8.5 grams of my lump of metal left.
but I'm bored of waiting so I'm heating the stuff up to speed the reaction.
It looks to me as though that meteorite has a layer of oxide on the surface which could be rather resistant to acid.
Hacksawing it in half would probably help (and it would be a lot less tiresome than turning it into iron filings.)
A proof of concept with a lump of scrap is a very good idea.
It looks like the lump I have would dissolve in a bit less than a week.
(Your meteorite may vary.)
According to thishttp://en.wikipedia.org/wiki/Sikhote-Alin_meteorite#Composition_and_classification
there's quite a lot of nickel in it, and I doubt that would help the photography any.
Once I have dissolved my lump of scrap I will add some nickel, just to see if I can remove it again.