If I recall correctly, the last new 33 WCF's were made in the mid 1930's. This round was only offered in the 1886, and the 1885 single-shot. This means that no new guns have been made for longer than some folks live. They might have been made available on a limited basis after this date as Winchester used up the parts, but the 71 was the successor to the '86, and the 348 was the successor to the 33.
Ever since the ol carbine slipped away, I've been looking to replace it, but the prices demanded even for examples that need a gunsmith are on the long side of ridiculous, especially considering that factory ammunition has not been available since the 1970's.
Dad's carbine was a shooter, and that's what this next 33 will be, when I find one for a realistic price. Wish I'd a known you before you gave that box away-was it Remington, or Winchester?