Topic: Wiper Arm Mystery?

[wunderwerks]

Went through a pile of arms today sorting out the good, bad and ugly. Most are 65, 66 and 67/68 all Trico. This one set of arms also Trico are identical in length to the other sets.  The difference is in the length of the stainless bracing sheath and the spacing of the rivets.  All the other sets match the one at the bottom.  Anybody have any idea of what the application may have been for the pair?