Can Anyone Tell Me if This is a Fake

Hi
and thank you for reading this thread.
I have just brought this Omega Seamaster Watch, but have doubts as to its authenticity.
I can see the pictures are not very good, i will try and get some better ones if needed,
but i was hoping from the descriptions someone might be able to tell me if this is a genuine watch
or indeed a fake / copy.

i cannot find a serial number as such on the movement just the following:
1020
Omega Swiss
seventeen
17 jewels
unajusted

There is a small round section with:
43
138441
Then the Omega Logo

On the inner case there is the following:

carrure lunette
PLAQUEOR G20 MICRONS
a Triangle with:
a badly etched Omega logo
Omega
watch co.

then underneath:
FAB SUISSE
SWISS MADE

Then a circle with LL in it

Then a box with:
1660256
3660861

This all looks etched.

Ozzie, I don't think it's fake, but it's not a very popular model, taken a bit of a beating, and that movement is filthy.

Similar model here:

http://www.omega-watches-expert.com/omega-watch-vintage.html

That 43 million serial number puts it around 1979, which matches the model nicely.

case bad with a lot of pitting. looks like a can of worms...... do not open...... kind regards. achim