4 speed with no vin#??? Warranty?

What do these casting numbers mean? C99126-3 H3 C99129?
They dont 'mean' anything, they just are production engineering drawing casting numbers. Those are early 70's case numbers.

On the issue of no numbers on vin boss, If we are talking about the above case, usually warrenty trans still had the pp833 plus assembly date code, but no vin code.

If we are talking about 1967 cast case, it is because the new castings just hadnt gotten into 1968 production to have a vin stamped into it.