It was a Catholic priest - Father Alphonso Gavin - who designed the most refined adjustable iron produced in the wood shaft era.  The mechanism in Gavin's club is located inside the hosel and adds comparatively little extra weight.  The blade has a normal profile and provides a playable head not matter which loft is selected. 

The clubhead has three basic sections: the hosel, the blade, and the mechanism. The mechanism consists of two pieces: a base piece that extends down out of the hosel and attaches to the heel of the blade; and a lock pin, the bottom of which is serrated, that runs down through the center of the base piece and interlocks with the top of the blade.  The base piece is marked "P-1-2-3-4-5" to indicate the loft selections.  Holding the blade in one hand and turning the shaft/hosel clockwise with the other hand loosens the lock pin inside the mechanism and unlocks the blade so it can be adjusted.  Rotating the shaft a few revolution in the opposite direction tightens the blade to the hosel.

Gavin filed for a US patent to cover his adjustable iron in February of 1926.  Joseph Novak, a professional golfer in California and State Open champ at the time, tried the club early on and liked it so much that he connected himself with Gavin's venture. The parties involved decided to use Novak's name for the club. Novak was soon involved with additional adjustable iron patents.

The Novakclub offered here is unused and everytning is original.   It is also exceptionally long, measuring 42 1/2" in length.  It is the best one of these ever! 

Novakclub—TCA 2, V2: p 457-458