An Abba ‘super-trouper’ fan has received a long-held dream surprise in the post after a 50-year quest.

After years of trying to get the autographs of all four of the 1970s Swedish stars on a photo of him meeting the band, Allen Lewis has succeeded.

The rare and treasured piece now has pride of place in his Tavistock living room, adding to his shrine to perhaps the most successful pop group of all time.

The quest began after he met the foursome when they were celebrating winning Eurovision with their song Waterloo back in 1974.

Eurovision took place that year at the Brighton Dome.

Allen was on duty as a mounted police officer on his white horse that day in the seaside resort and had his photo taken with the band for a press photo after bumping into them by chance in the street.

He later asked for the band’s signatures on the photo and received three of them, except Agnetha Faltskog’s. Ever since then, he has been urged by everyone to seek the holy grail, the full set.

The resulting photo would be a much-prized photo for any Abba fan, but particularly as in this case when the fan features in the photo himself with his musical heroes.

Allen said: “I finally gave in to friendly pressure. When I shared the photo on social media I was inundated with other photos and people saying what a shame it was that I only had three of the autographs. At the time it didn’t matter, I was just so pleased to have any at all. It was purely that Agnetha wasn’t around at the time to add hers.

“In the end I went through the fan club and the Abba Museum in Stockholm and they seemed to have pulled some strings. I was shocked and then overcome to get a copy of the photo in the post with all three autographs.

“It means so much to me and I’m really grateful to the people in Sweden. It’s my most treasured piece of Abba memorabilia and is in pride of place in my front room with the other photos.”

The original photo was blown up into a poster size by Dartmoor Photographic in Tavistock and Allen sent it off to the group for the signatures.

The story of the photo is interesting enough, let along the following search for autographs. The picture was taken by one of a crowd of newspaper photographers in 1974 outside the then Brighton seafront Bedford Hotel where they were waiting for the newly-crowned Eurovision royalty to come out.

Abba went for a celebratory stroll in the sunshine and who should trot along the promenade after taking his horse for a therapeutic splash in the sea, but PC Lewis.

He remembers: “It was just by chance I happened to be on patrol and met the paparazzi snapping away at Abba. I was happy to be asked by the photographers to snap me to posed with the group. I had a long chat with Abba, especially with Benny who loves horses and wrote ‘amazing’ on the photo. It’s a lovely photo with them in their purple and flowers.”