Translation:This morning was the last delivery.
Genau. Your analysis and interpretation of the two alternatives is exactly right.
Because you appear to be learning English as well, I offer this observation: use "better" instead of "more good." Similarly, "best" instead of "most good", "worse" instead of "more bad", and "worst" instead of "most bad". There may be some other English comparatives/superlatives with irregular form, but I can't think of them of the top of my head.
Same concept, but not as simple/direct as "this morning", which demonstrates that you understand diese as "this".
So, you're correct, but for the purposes of this course, you shouldn't expect die Eule to include that. No more than "During the first hours of the current day the shipment after which there will be no others occurred."