Tony Baker's collection is presented across 52 lots in Richard Winterton’s Antiques and Home Sale at The Lichfield Auction Centre in Fradley Park.
Specialists expect the exceptional haul to total £20,000 to £25,000.
Highlights include a gold Anglo-Gallic Salut d'Or hammered in the reign of Henry VI (1422-1453) valued at £1,800 to £2,200.
Also going up for auction is a Charles II gold coin from 1680 valued at £1,400-£1,600 and a UK Britannia four-coin collection in 22ct gold worth around £2,300.
A cased set of ‘The Magnificent Seven’ gold coins – one coin each from Australia, Canada, China, Mexico, South Africa, the USA and the United Kingdom – is estimated to fetch £1,600-£1,800.
Mr Baker passed away in May 2021 at the age of 83, leaving behind three children, seven grandchildren, and three great-grandchildren.
Born in Tamworth, in 1938, he started work as a lorry driver before joining the Army aged 19 and served for 25 years, finishing as Warrant Officer Class 2.
He went on to be a steward and managed Tamworth Progressive Club, where he put on variety acts and other functions.
After retirement he did much travelling, spending a lot of time in Australia.
Mr Baker and his wife Gill, who died in 2002, had three sons, Wayne and twin brothers Darrel and Dean.
Seeking professional advice on the coin collection, the family booked a free consultation at Richard Winterton Auctioneers in Tamworth.
“Dad was a bit of a character,” said Wayne, from Glascote.
“We knew he collected coins but it was a little bit of a surprise to discover quite how valuable his collection is.”
Phil Bridge, coin specialist at Richard Winterton Auctioneers, said to have 50-plus lots of high grade coins ‘is a dream come true’.
The Antiques & Home Sale at The Lichfield Auction Centre starts on February 7 at 9.30am.