Both Subetalodge and the collection guide say it comes from Oct 2011 collection - I just bought one but it doesn't give me the option to choose this items. It doesn't have a transformation note either.

What I'm doing wrong?

probably nothing. Sometimes they make a mistake, sometimes there's a coding error in Subeta. Try filing a TIcket in Help.

Have you tried doing a Search with quotes around donation collection name and "news" as search terms, putting in 2011 2012 2010 etc to see if it's like a year off?

Uh oh, if you do file a ticket can you post the results here so I can update my guide? :0 I just get all my info from subetalodge so I have no idea. Sorry about that .

I found this piece of news, looks like the item is broken somehow? I'll submit a ticket and share results :)

in that News it says "sliver" instead of "silver". This would explain why the link is broken. just copies out the words in the Item Name.

This might also be why it doesn't show in Collection, because the Collection calls for the misspelled item and the spelling it's been fixed since the original post/coding was made, but the call was not fixed: someone forgot to follow up.