Recalling the first time they met, Wakeford said he had found Wallbank "a real pleasure, believe you me - a real pleasure".
Wakeford has three children, eight grandchildren and 11 great-grandchildren.
Wallbank has four children, nine grandchildren, and 13 great-grandchildren.
Mary died 20 years ago on September 13. Isabel died about 10 years ago.
Back row: Ron's daughters Colleen Christensen and Pat Birley, their niece Dianne Temple, and Laurence's daughter Lyn Brooks. Ronald Wallbank and Laurence Wakeford in front. Photo / Andrew Warner.
Wallbank met Mary at a cabaret when he was in the Navy. Wakeford met Isabel when he was cycling down 13th Avenue eating an ice cream - "acting a fool", he said.
Both men served in the defence force during World War II; Wallbank as a sailor, and Wakeford in the Air Force fixing planes.
After serving in the war, Wakeford was given land for a dairy farm in a post-war ballot. He and Mary lived on their farm in Te Puke after moving from Auckland when he left the Navy.
Wakeford started a business fixing vehicle chassis, which is still running to this day in Tauranga.
Asked for tips on getting to 100, Wakeford said to "keep eating".
Centenarian brothers-in-law Ronald Wallbank and Laurence Wakeford. Photo / Andrew Warner
Also present was their niece Dianne Temple, whose mother Eileen was the sister of Mary and Isabel.
The joking continued as the pair were taking photos - directed to look at each other, Wakeford said Wallbank had to do it "whether you like it or not".
"Can I sue you for damages if they don't look nice?" Wakeford asked.