correct, the pump you got was wrong
i would say it was an older style, but it might be newer, both had larger fills.
the 68-69 powersteering pumps have a smaller fill tube. a-lot of them from the parts store don't come with the case, but some do. if you have to swap the case, be careful not to warp the case when your removing it. and when installing the new one, use a little powersteering fluid to lube the new o-ring before installing it.
hope this helps.
as with all parts, the store should have one that looks just like the one r that came off your car, if not, find a different store. napa is always a good store imop.
good luck