It's either a late 1952 or an early
1953 25' Cruiser built in California. There is no distinct cut-off number between those 2 years of 25' Cruiser production in California, so I can't say for sure the exact year in which it was manufactured. But it may have been titled in the year sold, so I'd go with a
1953 25' Cruiser, as represented to you.
Does the serial number on the certificate of title show 6139? If so, then someone at some state's title department may have mistaken a hand written "3" for an "8" on some earlier paperwork so typed it in as "1958" rather than "1953". It is NOT a
1958 Airstream. Enjoy your new vintage Airstream!