Got PPL in 1993. Had about 50 hrs. Didn’t fly until a few weeks ago. I can’t find my original logbook. Anyway to document those hours?
You can contact the FAA Airman Registry and obtain a copy of the 8710-1 application for your PP checkride. That will document most of your time.
Absent records such as receipts for your rentals or the like, the rest is probably gone.
But if you haven't flown in 30 years, it's probably not going to make a lot of difference in the path to recurrency. Start that process with the AOPA Rusty Pilot pages.
In your case, with 50 hours (and likely most of them prior to the flight test), Ron is spot on. The 8710-1 you filed for your flight test is the best way to reconstruct what you had.
For others who may have lost hundreds of hours with a lost logbook, the FSIMS link Ron provided has the reconstruction details that FAA inspectors look for, so it is the best guidance to follow to attempt to prove what time you had.
My personal tip - each time you complete a logbook page, sign it first, then make a copy of the page. Keep the copy, of course, in a safe location. This way, if you lose your logbook, you only lose a few hours that were on the last uncompleted page.