I agree, probably designed to be shipping tie downs. likely never used, as most if not all the shipping back then was never provided with that provision, unless deck cargo. For ocasional towage, I have used a short chain wrapped around the frame and extended with rope. I once single handedly moved a Vittesse with no brakes either. Using a crude but effective drawbar. wouldnt try it again, but it was only a journey of about 3 miles, across Yeovil, one quiet early Sunday Morning, when one hoped🤞 the local constabulary where still asleep!.
Pete.