The trail coincides with the largest ever exhibition of Beryl Cook’s work, being hosted by The Box to mark 100 years since her birth.
Thousands of people have visited the exhibition, which runs until the end of May, said the Local Democracy Reporting Service.
Council cabinet member for culture Jemima Laing said an extension of planning permission was being sought so the sculptures could stay in place until at least 2029.
The Jolly Sailor sculpture is on a bench outside The Dolphin Pub in The Barbican and the Cheerful Shopper is outside Plymouth Market.
The Bowls Player has been placed next to the Hoe public bowling green and Ruby Venezuela stands near the former Lockyer Tavern, which is now The Bank pub.
All of the characters are from Cook’s paintings and situated in the places where she painted them.
The artist was known for her vibrant and humorous work depicting larger than life characters in everyday social situations.
Laing said she and council leader Tudor Evans had been to visit the “brilliant” TR2 team hard at work on the new sculptures.
“We were particularly taken by extra large fish and chips that is going to be sitting in the box,” she said.
More than 1,000 people have scanned the QR code to follow the sculpture trail and six pieces of content on the Box channels have had more than 500,000 views on Facebook and Instagram.
“It’s by far the most far reaching content we have had on our channels this year,” she said.
“Plymouth is the home of Beryl Cook and the feedback has been brilliant.”