I'll help you "Get this straight":
Here is a 145.022-74 that is only 72 serials apart from the OP (eBay) watch discussed here.
As you can see, it has a step dial. Serial number: 35.579.XXX.
April 18, 1975 production:
Here is a 145.022-74 that is only 493 serials apart from the OP (eBay) watch discussed here.
As you can see, it has a step dial. Serial number: 35.579.XXX.
April 18, 1975 production:
Here is a 145.022-74 that is 1161 serials apart from the OP (eBay) watch discussed here.
As you can see, it
does not have a step dial anymore. Serial number: 35.581.XXX.
I cannot find the image of the extract of this one, but it also had a production date from around mid 1975 (May, I believe):
So if we look at these examples (including the eBay watch) we can conclude that the step dial goes away in around mid 1975, and around the 35.58X.XXX serial number range.
Now here is a 145.022-74 with a
lower serial number: 31.009.XXX
As you can see, it does not a step dial.
And a
later production date of November 28, 1975:
And to explain that clusterf@#k, you should read this thread:
https://omegaforums.net/threads/speedmaster-145-022-74-a-puzzle.92931/