That T-piece seems to be for Williams' version of the 'Zipper Flipper', only used on four games in the late 60's. Well, three really, since two of them ('Doozie' and 'Daffie') were Replay and Add-A-Ball variants of the same basic layout. The Williams unit was smaller than the Bally original, see below;
picture from Ipdb. The unit is shown in the closed position.
Apart from worries about copyright infringement, I suppose Williams used this arrangement due to their lack of a modular flipper unit (with all components mounted on a baseplate, and this in turn attached to the playfield). Bally had introduced such a unit in 1965, and their zipper unit appeared the following year.