I would just make an electronic (or a new paper but I highly recommend digital) logbook, put in single line entries for all the times you know (basically carrying forward from another logbook), annotate the logbook loss in there, and start fresh line by line. All my mil pilot training times were entered in a single line entry by aircraft type, because I was told the mil would keep track of my times. At the end of my first close out (end of pilot training), I wasn't satisfied with the tracking of flight time, so I started logging line by line. Also, my branch of service lost a lot of my flight time so I had to prove I flew it each close out. At the time of my logbook scrub in ground school, I showed my paper logbook with my civilian stuff, the single entries for my mil stuff, and my printout of flight times from the mil. That satisfied their needs. I have since created and used an excel sheet that has everything line by line civ and mil combined. Only my mil pilot training entries are blocks of times now, everything else is line by line.

Your situation probably won't matter for the regionals. May for the majors, but I know Atlas doesn't even look at logbooks anymore. Just start now, with all previously stated documentation, and you should be fine.