Re: fuel mixture
I think they had to replace a few power heads. Some motors seemed to get some internal rusting during long term storage at 100:1, so they went back on the 100:1 rating and changed the stickers to 50:1.
Yes, it was a very expensive mistake. Unfortunately, back in the 60's, they even said the 3's were good to run on 50:1 as well as the bigger motors. The 100:1 motors were the bigger mistake though and yes a lot of powerheads were rebuilt at OMC's expense. I don't believe it was because of rust taking hold during storage either. It simply was because there was not enough oil in the mix and engine parts went to pot very prematurely. Usually the pistons would suffer the most damage, because they are the parts that need the oil the most, in a non-friction type motor.
A lot of the reasons why outboard manufacturers were trying to make leaner running motors through the years, is because of the tree hugging liberals who lobbied to get the oil burning engines out of the water ways. They hate guys like me, who prefere to run 1957 motors with 16:1 mix. They would sooner have me crucified, than let me launch my boat. Now, as you see it, the political pressure has gotten so bad, that a lot of places will only allow 4 stroke outboards.
I'd bet that turned out to be quite an expensive mistake.