Circa 1963. 

The rotating head on a normal Mitchell 300 reel turns clockwise, when viewed from the back of the reel. Since most people are right handed, this presents two problems for the tournament caster: First, when casting for accuracy, most competitors used the forefinger, during the cast, on the rim of the spool to slow the cast. This does not work well with a right forefinger because the line is coming off the spool in the wrong direction. Secondly, It was difficult for the right hander to lift the line with his finger to catch it with the pick-up. 

Prior to the advent of this reel, a lot of competitors used the right hand version, the 301, because it eliminated this problem.

The rotating head on these competition reels turns counter clockwise (when viewed from the back of the reel). This was accomplished by using a 301 rotating head, and an intermediate gear to cause the head to rotate clockwise.

There were several different spools manufactured for these reels. This particular spool is a four stage design. The Manual pickup is tripple adjustable. The front (small part) of the spool is used to hand wind a shocker line. The other stages of the spool hold the main line.

Also, it has a "lock down nut" on the handle shaft to keep it from turning while casting. 

Only 60 of these reels were produced and only 12 are known to exist today.