No. There were no Proof Halfcrown coins minted from 1840 to 1849 inclusive.
All British Halfcrown coins, up to but not including 1920, were made from sterling silver (92.5% silver).
No. The 1970 British Halfcrown was minted as a Proof FDC coin only in cupro-nickel.
Such a coin does not exist. The last British Halfcrown coin minted for circulation was minted in 1967. The last British Halfcrown Proof coin was minted in 1970.
There was no 1805 British Halfcrown minted.
The last British Halfcrown was minted in 1970.
The last British Halfcrown was minted in 1970.
There were no British Halfcrown coins minted from 1865 to 1873 inclusive.
There were no British Halfcrown coins minted from 1752 to 1815 inclusive.
There were 1,710,946 1892 British Halfcrown coins minted.
British 1913 Halfcrown coins were minted in 92.55% silver only
Since the Recoinage Act of 1816, the British Halfcrown has varied from 14.1 to 14.2 grams. The British 1921 50% silver Halfcrown weighed 14.14 grams.
The last general circulation British Halfcrown coin was minted in 1967. The Halfcrown was subsequently withdrawn from circulation and demonetised on 1-Jan-1970.