Your looking for a 145.022-74 as they where made from 1974-1975. They have a somewhat unique dial shared with most 145.022-76 models.
Try these 2 resources. Speedmaster101.com and ilovemyspeedmaster.com . The former will show you the correct dial hint it’s the relation of the “S”in speedmaster to the “p”. It’s the first domed dial variant with the font of the preceding step dials. The later site will help you narrow down production date if you have the serial number.
The other thing is called a DNN or Dot Next to Ninety bezel. This is described at speedmaster101.com.
It will match my 145.022-76 actually, as mine is identical to a -74.
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