Any Info?

The trailer looks to be about 1969. I found a picture of a 1969 Orbit that closely resembles this trailer however, the emblem on the back indicates it's a Holiday trailer.

The serial number can usually be found on the right side or door side of the trailer stamped on the steel frame just behind the hitch. The serial number can be found either on the side of the frame in that location or on the very top. Try to remove any rust with a steel brush. Sometimes you need to remove the paint first if there is still some in the frame.