Offered here is the ultimate in giant niblicks: Cochrane’s super-giant!

Few collectors have handled a super-giant niblick; but, because it is so big and unlike anything else, most collectors have heard about it. The face depth of this monster is 4 11/16" inches at its deepest point. The back of the blade, not including any of the hosel, measures approximately 6 1/2 inches wide, heel to toe. 

When Cochrane’s super-giant niblick is seen in real life, its size impresses the viewer. When this club is held, however, its weight receives the attention—it is an incredibly heavy club. When this club is swung slowly, or even waggled, the shaft feels as if it would crack if swung at full speed. Not only is this club beyond heavy, its swingweight is off the charts....

It is thought by some collectors that Cochrane’s oversize clubs were originally made as display items or sales samples, to provide a larger-than-life demonstration of the clubmaker’s craftsmanship. Cochrane’s oversize giant niblicks were probably made sometime in the early 1920s.

36" original shaft and original leather-wrap grip.   This is one Giant Mamajama! 

As a point of reference, the Cochrane Super Giant Niblick that sold in Sotheby's 2007  "Jeffery B. Ellis Antique Golf Club" auction brought $11,250.  These are exceedingly impressive in real life.