Great Britain
George V Proof Shilling 1936 PR66 Cameo NGC, Royal mint, KM833, S-4039 (unlisted in proof). Blast white surfaces with an attractive cameo contrast. The last example of this type in proof that we sold was back in September 2012, where an NGC PR66 piece sold for $1,200. The coin on offer, being a number of years later (during which time the market has only gotten hotter), as well as possessing the desirable "cameo" denotation, should easily surpass that.
Estimate: 1500-2000 USD