A rusty old Porsche which doesn't work has been described as one of the most exciting discoveries in recent years — and it is set to sell for $700,000.

The Porsche 356A 1500 GS Carrera Coupe helped bridge the gap between the company's sports vehicles and racing cars when it debuted in 1955.

Porsche 356A 1500 GS Carrera Coupe that is up for sale. See SWNS story SWPORSCHE; A rusty old Porsche which doesn’t work is set to sell for £500,000 after being described as one of the most exciting discoveries in recent years. The Porsche 356A 1500 GS Carrera Coupe helped bridge the gap between the company’s sports vehicles and racing cars when it debuted in 1955. But this 1957 model hasn’t been driven for 45 years after its brakes failed a safety inspection in the early 1970s. Its original engine was removed and taken apart and, after the best part of half-a-century of neglect, the bodywork and wheels are covered in rust.

Parked in 1973 after failing inspection, this 1957 Porsche 356A 1500 GS Carrera Coupe is set to sell for $700,000  (Gooding & Company)

But this 1957 model hasn't been driven for 45 years, after its brakes failed a safety inspection in the early 1970s.

Its original engine was removed and taken apart and, after the best part of half-a-century of neglect, the bodywork and wheels are covered in rust.

Porsche 356A 1500 GS Carrera Coupe that is up for sale. See SWNS story SWPORSCHE; A rusty old Porsche which doesn’t work is set to sell for £500,000 after being described as one of the most exciting discoveries in recent years. The Porsche 356A 1500 GS Carrera Coupe helped bridge the gap between the company’s sports vehicles and racing cars when it debuted in 1955. But this 1957 model hasn’t been driven for 45 years after its brakes failed a safety inspection in the early 1970s. Its original engine was removed and taken apart and, after the best part of half-a-century of neglect, the bodywork and wheels are covered in rust.

The car has its original leatherette upholstery and 52,837 miles on its odometer.  (Gooding & Company)

However, as one of the most desirable classic Porsches, there is no shortage of interest from around the world in the unrestored sports car.

Gooding & Co, the U.S. auction house, has described it as "certainly one of the most exciting barn-find discoveries in recent memory."

Porsche 356A 1500 GS Carrera Coupe that is up for sale. See SWNS story SWPORSCHE; A rusty old Porsche which doesn’t work is set to sell for £500,000 after being described as one of the most exciting discoveries in recent years. The Porsche 356A 1500 GS Carrera Coupe helped bridge the gap between the company’s sports vehicles and racing cars when it debuted in 1955. But this 1957 model hasn’t been driven for 45 years after its brakes failed a safety inspection in the early 1970s. Its original engine was removed and taken apart and, after the best part of half-a-century of neglect, the bodywork and wheels are covered in rust.

In its day it was Porsche's top of the line model.  (Gooding & Company)

They have given it a guide price of $700,000 ahead of its sale on March 9, 2018 at Amelia Island, Florida.

David Brynan, Gooding & Company senior specialist and Porsche expert, said: "This was Porsche's top of the line road car and one of the most exotic sports cars of the 1950s.

Porsche 356A 1500 GS Carrera Coupe that is up for sale. See SWNS story SWPORSCHE; A rusty old Porsche which doesn’t work is set to sell for £500,000 after being described as one of the most exciting discoveries in recent years. The Porsche 356A 1500 GS Carrera Coupe helped bridge the gap between the company’s sports vehicles and racing cars when it debuted in 1955. But this 1957 model hasn’t been driven for 45 years after its brakes failed a safety inspection in the early 1970s. Its original engine was removed and taken apart and, after the best part of half-a-century of neglect, the bodywork and wheels are covered in rust.

Its original engine is in parts and needs to be rebuilt. When it is, it goes in the rear.  (Gooding & Company)

"They have always been sought after, so most have been restored at least once.

"To find a car that hasn't been seen in 40 years, and that retains so much original character is virtually unheard of."

The car is being sold with the original engine, which will need to be rebuilt.