Hello vodland,
Thank you for participating in the Ask the Experts Event. As to your question, if I am reading it correctly you actually experienced a capital loss of $1,875 ($2,500 less $625), correct? You can request a 1099-S from the company who handled the bankruptcy process, but I haven't seen very many of them issued when they should.
Either way, you can just enter the information as a capital transaction on Schedule D. Enter $625 as the proceeds and $2,500 as the cost basis. Keep as much documenation as you can for your tax files, but I wouldn't worry too much about not having your original purchase documents. If the IRS comes knocking on your door you can just explain and they should be fine.