If you work for any company that has a computer then the records do exist somewhere. A letter on company letterhead stationary signed by the VP Flight Ops or Director of Crew Admin, or what ever the titles are in your company would be acceptable.
The letter should include total time P1 P1US and P2. Additionally, simulator time should be given but it's not required. There will be a gereral statement about being employed between DD MMM YYYY through DD MMM YYYY. Plus any postions you have held during your tenure at the company.