Wayne is correct. Back in 63 Scotty did have a dropped interior floor but you had to step up into it before stepping down into it.
1964 was a very transitional year for Scotty. Some had it, some didn't, goofy colors, the HiLander...bump behind the door, some with the bump in front of the door, They tried a 13' Hilander, Mattress model, Goucho, and so on. Only the stamping on the tongue can verify a 1964, and that only verifys when it was stamped....could have been an older one.
My guess is 65 or up. It looks the same as my 66.
It doesn't matter though, the one pictured is a lot more convenient, a definite Plus.
This is the Passengers side of a 1963.
Happy Trails
Len