Lucky me - I bought 10000 Ether for 5BTC in the pre-sale and forgot about them until just recently. Yahoo! However, now that I've sold some at a profit I'm going to need to prove the date and quantity of purchase for the tax authorities and I'm not sure they'll just accept an email dated 2014. Even if they do the confirmation email doesn't state the quantity purchased. Idiot me updated all my BTC wallets since then without taking screenshots so the list of transactions no longer includes the transfer to the bitcoin address I used to purchase the Ether. Didn't realize that an update would wipe the transaction history to date but there you go.
Does the Ethereum Foundation provide any kind of proof-of-purchase for people who bought in the pre-sale? If I could only find proof of the quantity purchased then I would at least have a continuous 'chain' of proof [Press release stating quantity of Ether per BTC - purchase confirmation email - price of BTC on that date - ... quantity purchased...].
This is important as in Germany if I can prove I've held them longer than 1 year I won't have to pay tax. I would really appreciate some help!