I've seen 'em. Think they were on a Dodge. You probably already did this, but as a btw, a google search using an upload of the image didn't tell anything. I recall it being on early '60s car...a Polara maybe. Went looking, found this: 1963 DODGE 330/440/500/POLARA/MAX WEDGE TRUNK EMBLEM | eBay Doesn't mean what is shown is true. PN stamped on back is different. Casting OEM is the same. **edit** All of the above written when there were zero posts to the OP. I took too long looking,'eh?
I answered this question with an ebay link that showed the part for sale. Not sure what happened to the post. One tab showed it, this tab refreshed, does not. There is a picture of the same emblem, advertised as being for a Polara..'63 I think. Said to be from the deck lid.
Most likely 63/64 Dodge 330 or 440 Coronet. They are very close, if not right on as the emblems on my Coronet 330 post car. I'll try to find pictures of it in my photo albums.
definitely 64 Dodge 330 (not 440 or Polara) rear quarter, but may have other applications around that time. They were on the low trim cars, so consequently on most of the factory race cars. They should be worth a bundle to someone doing a Max Wedge or early hemi restoration.
Found it on several pages of the 1963 Mopar Parts Catalog (published January 1964). It is the Fender Side Name Plate for the '63 Dodge 330 (2dr, 4dr and wagon) and the 440 (2dr, 4dr and wagon). The nuts that hold that on are part number 152-260.
BTW... where's a time machine... I just looked in a Mopar Collision Parts List book that was published in 1963, those emblems sold for the unbelievable price of $1.50 each.