In a catalogue from 1989, a Crest is shown with a steel nib; I think I’ve seen it in one of our local shops (I seem to remember the steel nib and riffled grip kept me from buying it), but wouldn’t testify to that under oath. Earlier this year, one was offered on eBay/Germany, but I didn’t realize, then, how interesting it was.
Another catalogue, from the early 90-ies, shows a further development of the Crest: it still has the narrow plain band at the bottom of the cap, soon to be replaced by a much broader one, but it now has a gold nib.
The left page has a big enlargement of a Triumph 14K gold nib (also reproduced by Jim) which allegedly belongs to the Sheaffers Crest of the opposite page. There, however, the nibs are doubtlessly 18K (and remained so during the whole production period). That’s what the catalog text says, and even more conclusively: I own one of those pens myself –and love it dearly.
Jim justifiably doubts if the 14K nib has ever been produced. I would have bet against it ... until today.
I just stumbled across what may be the missing link: Pen Mechanic Bill Enderlin has, on his home page, a modern Sheaffer Crest listed which is actually said to have a 14K gold nib...