Its the "nut" behind the wheel which determines whether it may be safe or not.
I have retrieved dozens of
fiberglass trailers in various states of repair.
No one would dare recommend that you tow without hooking up the brakes, but many of them would pass you traveling well over the speed limit while towing a 16.
Which is worse?... 75 without trailer brakes or 60 with them.
You will just have to make the call.
Bob is right ... it shouldn't take much more than an hour or so to have it done.
The CX9 is a competent TV for a Scamp16 and you are legal without trailer brakes anywhere within those 300 miles of your home which you mentioned.(except maybe Canada)