Omega watches with stickers inside the case back

Hi,

I recently found out that one of the vintage Omega watches I bought years ago when I started the watch collection hobby had a sticker glued on the inside of the case back. Then I found several watches like that floating in the internet, including one that was posted in this forum 3 years ago.

Usually, they are stickers stamped on the case back meant for a quartz movement, but just happens the case is the same used in a similar mechanical watch. So far, they all use 10xx calibers.

What's the story here? I know that Omega used to strick thru reference numbers and print another one in many of the 50-60 watches and sometimes use a Seamaster case back on a Speedmaster (such the the TV Dial chronograph), so I wouldn't be surprised if this was something they did in the 70s to save money. But it looks too cheap really.

What do you think?

Probably as insulation between the metal caseback & the movement ?
interesting observation, the only Omega stickers I know are the STS-1 logo Speedmaster ones
45 years ago...
.

This is another one. Same characteristics, case back meant for quartz movement and movement used here is 102x. The first one I posted above is 1012, so they are all in the 10xx family.