In a message dated 10/7/2010 10:03:15 A.M. Eastern Daylight Time,
mcneely4@COX.NET writes:

Well,  the metal ones in your van are DIY pieces, because the original ones
were  plastic

The early vannies had metal tees  up to about 1985  IIRC    plastic ones
came on later vannies and are still out  there.  later  mark d