I remember seeing some new bricks reusing (probably updated) older variation of the mould. So this kind of information isn't always accurate.
Here what Rebrickable tells about variations of Brick 1 x 2:
There are three known mold versions of this part:
3065 Brick 1 x 2 without Bottom Tube This is the original version,
introduced in 1955. The inside has no ...
The mane seems to be based on 64647 Minifgure Plume Feather Triple Compact in either trans-orange or trans-neon orange colour; each plume is mounted on a 85861 1 x 1 round plate wih open stud.
The hooves are 47458 1 x 2 x 2/3 Curved Slope Wing End.
The leg joints seem to be tow-ball joints. See parts 22890 1x2 plate with tow-ball, 14418 1x2 plate with tow-...