i have seen quite a number of listings tonight on ebay for british £5 coins from 1972, 1980 and other early dates. do not under any circumstances be tempted to buy any of these coins as the cupro nickel £5 coin was first issued in 1990 to mark the queen nothers 90th birthday, any before that date back to 1972 of the same size and weight are 25pence crowns and wortha maximum of £1 each. these listings are i feel a deliberate attempt to fool buyers into believing that they are buying a genuine £5 coin.
Can you post a few links? Right now, I'm heading to bed and will be too busy and too lazy tomorrow to search for and try to determine which listings and seller(s) you are referring to. Thank you.