Thanks to you all. My question is whether this watch solid gold or just gold plated?

 

Well, the Omega Constellation is no cheapo watch. It's unfortunate that they would ruin it by putting the Arabic lettering on it. I suppose someone likes them or they wouldn't sell em.

 

Plaque G is written in the buckle, right?

 

Yes Barth Plaque G.

 

You'll have to get it opened up to be certain, but googling the watch reference number only brings up 20 micron gold plated.