The original Yeti forks had several small changes over the years. The original had campy drops that were modified. The leg end caps were saw-cut from solid bar at an angle. The steerers were made from raw tube, threaded and had a .833 (13/16") ID for BMX stems.
The next version had laser-cut dropouts, flat cut end caps and steerers that were internally reamed to 22.2mm (7/8" or .875") This version has the crown ring welded to the steerer in an earlier operation with leg welds covering them.
The next version used tru-temper steerers and legs. Most of these were recalled and destroyed.
The next version would be the Accutrax. They should be the same as the second version.
Of the forks in the earlier thread, the left one is a tru-temper/yeti. The right is an accutrax.