I agree with Pete; pick up the connectors and a 12V circuit tester before you leave home since you can always return them if they are not needed. How big is the Scamp
? The equipment requirements for the 16' are quite a bit different than the 13'. As Donna indicated, the standard ball for the 13' is 1 7/8 and the 16' is 2". The 13' can use a class A hitch while the 16' requires a B or preferrably a C. Hitch height is 18" to the top of the ball for the 13' and 22" for the 16'
The 16' will require a brake controller (the 13' may not). To fuzzy up things a bit more, Scamp changed the design of the 7-pin connector around 1998 and the original is almost impossible to find. This would require rewiring the trailer connector for a 7-pin Bargman.
I went through the same sort of stuff when we purchased our 99 Scamp 16' in the DC metro area last year... I also made sure I picked it up during the week in case I was still short of parts (or the tires
were so bad I couldn't tow it home).
Get as much info as possible before pick-up. Best of luck with the purchase.