this will cost you a lot, take notice, it costs somewhere around 500,000,000,000 in yen.
50-200 USD
100-1000 USD
I assume your rifle is an SMLE in .303 British. If so, value can range from $300 for an unmodified specimen in fair condition, and up to about $700 for one in excellent condition. You will really need a hands-on review. Take your rifle to a gun show near you where dealers and collectors are gathered in one spot for your convenience.
Do you mean a Pattern 1917 rifle that has been rechambered to one of the .300 cartridges (and if so, which?)? sales@countrygunsmith.net
The British New Penny coin was first issued in 1971.
http://www.milsurps.com/showthread.php?t=4025
Would need more info on the rifle, caliber, model, condition and images would be nice
100-1000 USD depending on EXACTLY what you have.
Any Halfpenny coins circulating in Gibraltar in 1917 would have been British Halfpenny coins.
50-300 usd
100-1000 USD depending on specifics
Between $400 and $800, deducting up to 70% for poor condition.