1958 Royal Mint Proof Gold SovereignHa,The best of the Gillick Portrait of Elizabeth II seriesand is an extremely rare piece.
Particularly,PR69 Only one copy in the world as the highest authenticated copy of DCAMis the ultimate value for collectors and investors.
Because they are rarely available in the market,Opportunities to obtain them are extremely limited.I am sure you will.

Design Features and Attractiveness

Surface (obverse)

Design: Gillick portrait of Elizabeth II (facing right)
Designer: Mary Gillick
[Features
The first portrait of Elizabeth II, featuring a youthful design without a crown
(Known as "Young Elizabeth" or "Gillick Portrait").
Traditional design used for the Sovereign between 1953 and 1967.
The soft and refined sculpture harmonizes with the proofed mirror finish.
Proof editions are especially rare and rarely available on the market.
[Imprint] [Imprint
Elizabeth - II - By the grace of God - Queen - F : D : +
Meaning, "Elizabeth II, by the grace of God, Queen of England, Defender of the Faith."

Reverse side (reverse)

Design St. George and the Dragon(St. George on horseback facing right)
Designer: J. J. H. Harris Benedetto Pistrucci
[Features
Traditional design adopted by the British Sovereign since 1817
Proof finish highlights the dynamic movement of St. George
B.P." stamped on the exergue (ground) and the year "1958

What is Proof Specification (Proof)?

Unlike regular circulating sovereigns, these coins are specially manufactured to proof specifications and are extremely beautiful.
Mirrorfield (mirror finish) background and frosted (cameo effect) portrait/design area
Rated PCGS PR69 DCAM (Deep Cameo), which confirms a stronger cameo effect than normal proof coins.
Extremely sharp carvings and perfectly preserved.

Rarity and market value

Rarity:R4 (Marsh Standard)) *Estimated only 11-20 proof plates in existence.
PCGS:PR69 The only one appraised in DCAM grade (single finest)
market value
1958 proof sovereigns are extremely rare and rarely come on the market
Popularity of Gillick portrait of Elizabeth II soars in 2020s
Proof specifications in particular tend to trade at a premium.

The ultimate piece for collectors and investors

(1) The pinnacle of the Gillick Portrait Series
1958 Proof Sovereign is the rarest of the Elizabeth II Gillick series
Proof editions of Gillick designs are far less common than quicksand currency and are coveted by collectors.

Only one of its kind in the world.
PCGS PR69 DCAM's only authenticated item (single finest)
Almost no marketable product available and prices are expected to rise in the future.

(3) Beautiful proof finish
Strong Cameo effect and outstanding visual beauty
Special manufacturing techniques that differ from ordinary circulating coins

(iv) Long-term asset value
Elizabeth II Gillick Portrait Coin Prices Skyrocket in Past Decade
The highest appraised products are expected to continue to command premium prices.