Yes, I do have 10,000s of thousands of miles towing with my 72 and 61 wagons as well as my GTOs.
If you have any welding skills, or know somone who does, you can find a used receiver hitch (even on off of a pickup is possible ) and adapt it to fit your Bonne. I can also check my yard to see if I have an extra.
A rear sway bar is a good idea, I also recommened air shocks and air bags (air lifts). It is great to use both instead of depending on one of them. HD springs are a good idea too. Find a set off of a '70 wagon as they are heavier. Again, I may have a pair, I would have to check my yard.
make sure you are using a dual axle trailer with elect brakes on both axles.
For safety and better control, mount your brake controller as close to your st wheel as possible. This makes it easier to use trailer brakes without having to take either hand off of the st wheel. Mounting it way low and far from the st wheel , as most do, is a bad idea.
I also highly recommened an equalizer hitch. These units make a world of difference in stability, you probably can find one used to save money.
A transmission temp gauge, cooler, 4 row radiator, HD fan clutch.
Another thing I strongly recommend is checking the load rating on your rear tires. After many rear tire failures while towing (!), I have gone to light truck tires that have heavier load ratings and the problem has gone away.
On my wagons, I use 235/75 -15 LTs or 10.50x 31s on the back of my wagons.
I adapted a GTO rear sway bar for my '61. With a bit of thought, you can fab a rear bar from somwthing too if you can not find a kit or don't want to spend that much.
Finally, depending on your experience with towing, take it easy on your speed, be careful when big semis blow by you and on down hills, keep a finger on the trailer brake controller and use it. Remember, to change your settings on the controller as needed. It should not be a 'set it and forget it' componant. I use higher setting on the freeway and lesser ( as needed) in town.
Always leave lots of room in front of you with whatever you are towing with.
If you have any other questions, just ask.
Steve Barcak
www.pontiacheaven.org