The trailer in the linked ad appears to be from about 2005 or newer. That was when Bigfoot rolled out the 2500 series of all-molded, four-season trailers with the low belly band. As far as I know, there was no 25' model prior to then.
I'm going to assume the title
says 1964, which is clearly incorrect. According to this thread
, Bigfoot started production of molded trailers in late 1977 as 1978 models. Definitely not 60's.
If this is a post-bankruptcy unit (2009+), you can probably call Bigfoot with the VIN
to get the true date of manufacture. If it's older, they will tell you, but they do not have build records of pre-bankruptcy units.
We've seen a lot of errors on titles for vintage units, but this one is not vintage and seems serious enough to warrant attention and correction prior to a sale.