This weekend, I was able to visit with a premier collection of wings and saw a number of beautiful silver (non-gilt) USN wings. Including those made by BB&B, Robbins, and at least 2 other unique patterns.
They still seem to be much more common than one would expect for a wing badge that was only worn for about a year and a half. But clearly I am wrong.
Jumping in a little late. You might want to take a look at this gent. Then RAdm Joseph Reeves was JCL came to aviation as a senior officer so he could move to an aviation command. He was the first USN flag officer to wear wings and the first 4-star. Note I say wings, not wings of gold. Reeves was an observer, not an aviator. Entering Pensacola in June 1925 as a 53 year old Captain, Reeves completed the Naval Aviation Observer Course in September of that year. Oddly enough, he commanded the collier USS Jupitier when she was first commissioned (1913) and, years later, after she had been converted and renamed USS Langley, his first assignment after receiving his wings was as captain of Langley.
This portrait photo (official USN) was taken after his promotion to Rear Admiral in June 1927. Let me quote his biographer, noted naval historian Tom Wildenberg: "Note the silver wings on Reeve's breast. The design for these Naval Aviation Observer wings - the second style authorized by the Bureau of Navigation on 26 January 1927 - was identical to those worn by Naval Aviators except that it was in silver instead of gold. A third style, also in silver but with an 'O' circumscribing a plain anchor, was promulgated by the Bureau's circular letter 71-19 issued in October 1929."
My take is (a) I don't believe Reeves would have worn gold wings to which he was not entitled. Moffett at BuAer would have had his head. And ( if there were no aviator style wings, but in silver, in use, then the circular 71-19, whatever its wording, would not have drawn attention to their replacement.
I have added an enlargement of Reeves wings in this photo, obviously the same style as the aviators, pin on type.