1970 admiral 601?

This poped up in the ebay thread, and I had a question regarding the movement. Links to ebay but I've also included the pic of the cal, as well as two photos of the reference cal


View attachment 1819649 Question for the experts on this one.

Clearly the movement should be a 601, and from what I see, it looks identical to reference photos, with one thing I'm having a hard time rextifyinf.

I see pretty clearly that this admirals "601" looks stamped "501", a much older auto movement.
Maybe I'm not reading right but I've attached some images to explain

The photo from the listing, the first digit looks like a 5 to me. I figured, could be a trick of the light, but when I looked at reference movements (attached) the top of the six, much more visible in the reference photos, is clearly rounded at the top of fhw 6, while the photo of the admiral's "6" (looks like 5 toe) is clearly flat on the top, and the angle down from the top is clearly slanted.

Additionally, the omega signature above the movement caliber has a 1 stamp.

If I'm stupid, call me out, I know enough to know that seems inconsistent, but I'd not be shocked if there's some backstory there...


Slight update, checked numerous serial guides, both manual and database, and they concluded that serial number was indeed produces in 1970which is appropriate for the watch, but the 501 was only produces from mid fifties to the very early 60s

Where on a 501 movement would it be stamped? Is that in the same place as the watch you are looking at?

Thanks guys. I knew the movement looked correct, escapement, bridges. Are the cal numbers hand engraved?