Gather I-94 printouts, passport pages, flight and lodging records, meeting calendars, correspondence with the seller, letters of intent, deposit receipts, and any escrow instructions. Include the current purchase documents. Gaps can often be filled later from bank or carrier records, so start assembling now rather than waiting for a complete set.
Match documents to the timeline day by day
Place each record against its corresponding date so the account is verifiable rather than asserted. Where a deposit was paid, keep the instruction, the wire confirmation, and the contract clause governing refunds, because whether such money counts as committed at-risk capital depends on the actual terms. Keep source and path of funds evidence too; a closing balance alone does not show lawful origin.
Retrieve in order of decay, then work in order of dependence. Bank archives, carrier records and hotel folios age out of the systems holding them, so request them first even though they will be filed last. Documents you can produce yourself, such as the chronology, the schedule of payments and the list of participants at each meeting, can be written while those requests run.
Hypothetical example: a purchaser of equipment from a packaging-line installer waits until the investment memorandum is finished before asking for statements from an account closed the previous year, and the record that would have shown where the deposit came from is no longer retrievable. Source and path of funds evidence behaves the same way: the trail is easiest to document while the accounts the money moved through are still open.