I very much agree. Even if it is a purist show truck, someone will have to lay in the floorboard and look under the dash to tell the difference. The knob mounts back in the original hole, and you can change the knob color if desired.
The one I got from carandtruckshop.com has a chrome knob, shaped like the original.

57 GMC LCF 370
55 John Deere 40-W
59 John Deere 430-W
2000 GMC 4x4
56 John Deere 420-W
Pix on Photobucket