My 1965 Buick Parts Book lists the following: Group 9.647 Part #1366121, All manual antenna masts except Riviera. Years ago I picked up a NOS antenna at a swap meet. It was a prefect match to my original mast. However, the label on the package tube was labeled : GM Parts Group 9.647 Part #1371183. Same as 1964 & 1965 all except 9000. The antenna was definitely NOS, which leads me to believe that the same part could have been used on many GM models and years, with different part # associated with it.
Since the antenna was made of stainless steel, you should be able to find one at a salvage yard. With a little steel wool, it would look like a new one.
Good luck,
John Egel
