IMO, there is no "too old". Of course, there IS junky or good condition.
If the trailer is in good shape, and everything works as it is supposed to, and the tires are not over 6 years old, and the title is good and clear, I would not care if it was a 1960 model!
CM1, USN (RET)
2017 Jayco TT
Daily Driver: '14 Subaru Outback
1998 Dodge QC LWB, Cummins, 5 speed, 4X2
2 Kawasaki Brute Force 750 ATVs.
Pride Raptor 3 wheeled off-road capable mobility scooter
"When seconds count, help is only minutes away!"