Towing a vintage car?

I don't know if it would be practical but, an early 60's Chrysler would be a cool toad.

Add me to the trailer recognition.

I would put it on a trailer and let the trailer hubs take the miles. It is easier on the very old drive train.

Manual transmissions are NOT necessarily towable. More often than not, the lube is distributed by the rotating cluster gear which is powered by the input shaft. When the engine is not running, the input shaft is stationary and no lube is distributed. The center mainshaft needle bearings and output shaft ball bearings will eventually run dry and self-destruct. Be sure you know how the transmission is lubricated before setting the vehicle up for towing four down!
SOME older automatic transmissions may have a rear pump driven by the output shaft. That pump MIGHT provide lubrication to the bearings. Such vehicles often can be push started by getting it up to 35 MPH in Neutral, then putting the transmission in drive. The rear pump will supply sufficient hydraulic pressure to engage the clutches or bands.
A driveshaft disconnect may be the best bet for towing four down. It is likely that a good fabrication shop will have to custom design and install the baseplates to match the towbar.
A trailer to load the vehicle might be an option, depending on the likes/desires of the operator

Haven't bought yet, not looking for a show car. Probably buy a nice driver condition so dings, etc. won't be a problem for me.
I do use a Readybrake now for my truck and Tahoe. Great towbar.

I wouldn’t think the automatic would take kindly to being towed four down. Perhaps the manual could but perhaps. I assume these are show cars that you don’t want dinged up? If so you might want to consider trailering it under cover.

Remco Driveshaft disconnects are available through Superior Driveline: https://www.remcodsc.com/coupling/

I tow a '97 Ford Aerostar (rear wheel drive) with no problems and no miles accrue on the odometer - the transmission remains in PARK while being towed.

The baseplate is another issue. Make sure your installation is up to the task.

I use and prefer the NSA's ReadyBrake https://www.readybrake.com/store/c3/Supplemental_Braking_Systems.html It's given me great service for many, many years.