The original hoses on some of those old models used a construction technique quite different than modern hose. It was done much like hydraulic hose. The hose was assembled into its recieving fitting by a combination process. The fitting was bade of two pieces which screwed into one another at the same time one piece screwed into the inside diameter of the hose and the other screwed over the outside.
I am thinking the one guy was going to do this. The hose used in such lines looked to be braided and was usually reddish.
All later versions used crimped fittings. Many shops can cut the crimped section, weld in new barbs and recrimp new hose to specialized formed assemblies. This method is best because most shops able to do this are also using the barrier hose recommended for 134 conversions. We have been doing it that way for about 12 years, not because be planned on converting originally. We did it because the hose worked better.
Bosch Master, ASE Master, L1
33 years MB technician