You have asked whether the crankshafts are identical. Briggs lists dozens of crankshafts in their parts list, sometimes dozens for just one engine size. The differences are some minor detail, and the changes were often made for some reason that is not apparent to people assembling or using the engines. So, I'm not sure anyone can answer your question - the best prospect I can think of is that AVB will know. So far as swapping them is concerned, in cases where the engines are of the same bore and stroke (as they are in this case) and were made close together in time (as, again, they were in this case) you nearly always can swap them, but there can be no guarantee without trying it, or finding someone who has already done it.
Now that you have spark, the next question is whether you have compression and whether it runs. If it has spark and compression but won't run, the first test to make is to put a small spoonful of petrol into the cylinder through the spark plug hole, and see if it starts then. It may only run a couple of seconds, but if so, you know your only problem is in the fuel area, usually the carburetor. We can discuss that more specifically if necessary.
