Not all of those are ancient history.
Thirteen of the 65 incidents came to the Scouts' attention since 1992, when it became mandatory to report everything suspicious to police, said the report by investigators at KPMG.
The review was released on Monday.
"I guess the most troubling part of the report is there are times where our processes and procedures and our policies and our people failed," Steve Kent, the chief commissioner of Scouts Canada, said in an interview with The Canadian Press.
"We failed to follow our own policies and procedures,"
As soon as the auditors pointed out the unreported incidents, Scouts Canada gave police all the records it could find, Kent said.
"I can now say confidently that every record we have, related to suspected abuse, has been shared with law-enforcement authorities across the country."
The youth organization has touched the lives of 17 million children in Canada since 1905. In 2011, it had 102,609 members and about 24,000 volunteers. In its heyday in the 1960s, the organization had almost 320,000 members.
Scouts Canada asked KPMG to go through 64 years of records after a CBC investigation last fall uncovered dozens of confidentiality agreements that essentially prevented victims from speaking out over the years.
At first, the organization told KPMG there were 350 instances that needed reviewing. Then, as the auditors dug in and found more evidence, that number grew to 468.
But KPMG said the records are so inconsistent, poorly kept and disorganized that it can't be sure it has uncovered everything.
"The state of these important corporate records was surprising to both KPMG and Scouts' current management," the report said. "It is clear from the state of the files that Scouts was not managing these matters centrally or learning corporately from past mistakes."
But shoddy record keeping does not mean malicious intent, Kent said.
"I think one of the most positive findings is that the report didn't reveal any systemic attempt to cover up or hide any information relating to incidents that occurred in the past," he said.
"So, I'm relieved by that. It really confirms what we've been saying....all along."
The KPMG report found a significant improvement after 2001, when Scouts Canada centralized its information and set out national protocols.
The organization now keeps a central, electronic, internal "confidential list" of people that are not considered suitable for involvement in Scouts. But in the past, this list was not always up to date, nor could it be readily shared with everyone in the country.
The mere existence of such a blacklist is controversial, since it contains suspicions not yet proven.
There are still 64 cases of suspected sexual misconduct in which KPMG is still not exactly sure what happened. Kent said Scouts Canada has contacted every single organization across the country, required affidavits and "left no stone unturned" to collect more information and hand it over.
The report said that before 1992 — when the law changed to require mandatory reporting to police — authorities were aware of 65 per cent of the cases at Scouts Canada. Post-1992, the authorities knew of 85 per cent of the cases.
Overall, authorities were aware of an average of 73 per cent of all records — an unacceptably low level, Kent said.
He would not discuss how many charges had been laid or how many investigations into sexual abuse were underway.
As a result of the review, Scouts Canada is beefing up its screening and training of volunteers, as well as offering counselling to victims.
"Scouts Canada is a safer organization than ever before in our history," he said.
The process of subjecting the organization to an independent review and then making all the findings public should help the victims, Kent added.
"We've made our organization incredibly vulnerable by going through this process."
KPMG identified some ongoing gaps in Scouts sexual-misconduct policy, including inconsistent communications with Scouts in other countries, and the inclusion of some unscreened volunteers in Scouting activities.
The report also pointed out problems with resignations. The investigators found some cases of volunteers being allowed to resign instead of being suspended or terminated.
The report pointed to inconsistencies in dealing with individuals who had been involved in sexual misconduct but not while involved in the Scouting movement.
KPMG also found a lack of policy about how to inform parents of all Scouts-sanctioned events and pointed to two occasions when volunteers took advantage of their positions to engage in sexual misconduct at events that were not sanctioned.
Kent said the organization has set up new procedures to deal with those gaps, but that it will take time to fix the entire system.
Much of Scouts Canada's history is also the history of other organizations in Canada decades ago, Kent said, and he urged all groups to work together to improve protocols.
He also said the audit showed a need for a national child abuse registry — something the federal government could take the lead on, but could also be spearheaded by volunteer-based youth organizations.