Help with Constellation

I'm new here so hi to everyone.
I would greatly appreciate help with identifying the Omega in the pics.
I have searched everywhere and can't seem to find anything on it.
The diameter is 38mm ex crown and just over 6.5mm thick.
I presume it is Quartz due to how thin it is, however it does not say anything on the dial.
I am interested in learning anything about it.
The case back has no lip or recess that I can open it with to change the battery and there does not seem to be much of the crystal showing to access from the top. Is a special tool required to open it.
All is original including signed buckle and strap as advised by the owner, however the crown is unsigned. Is that unusual as it has had one owner purchased retail in 1991 or 92.
I'm also interested in approx. value.
I have a few vintage Omegas in my collection plus others, which I have serviced or restored.
All other Constellations from this period seem to be mostly claw type.
Cheers,
Gazman43

Hi mate, welcome to OF 😀

I am sorry to be the one breaking the news, but the above isn't a genuine Omega, it is a pretty generic fake. Constellations of this era have a more distinctive look and the caseback text is a big tell.

That’s a bad fake.

As a learner driver I focussed on not being able to recognise it compared to any other reference ever seen, and the shape of the logo - however was there actually a constellation that looked like this at all?

Welcome!
This is however a bad fake...

That's great I thought I was going mad not being able to find it.
I thought a few things were odd myself, it's great to get confirmation.
Unfortunately I will have to let my mate know, I hope he didn't pay too much for it back then.
Thanks so much for all your help.
Great site.