I tried to find out if Ike really carried a #63 pattern and what I discovered is that I think someone not familiar with the Case numbering system and many years prior to the internet and vast amounts of information at our finger tips misinterpreted and reported what Ike really carried. I found two of his knives both are #6333 the Case #33 small stockman, I am guessing who ever reported Ike's knife most likely was not a knife nut, said it's a small pen knife generically speaking how most would refer to any small knife and it has a #63 on the tang, but what Ike really carried was the Case #33 small stockman and Case's system the 6 being jigged handle and the 3 being 3 blades. I read somewhere during Parker years Case reintroduced the #63 as the Eisenhower pattern but can't seem to find that info so....?
I did read that he did give away the #63 what the is known as the Eisenhower so it is possibly just a coincidence that the prefix to his stockman is 63 and the knife he eventually would giveaway is the pattern #63, so there is a connection to the #63 pattern.
"During the late 1950s, President Dwight D. Eisenhower arranged a three-day fishing trip to Quonset Point Naval Air Station in Rhode Island. He had five sailors convert a PT boat into a fishing vessel. At some point during the trip, the President gave each of the five sailors an 08263 Eisenhower pattern, handled in mother of pearl."
So as there are no rules for knife nuts, I'm sure Ike had more than one knife, perhaps he carried it latter in life after he started to gift the patten but here are some pics of Ike's knives.
Pete