I recently bought a job lot of Omega dials, including the one below. The back of the dial is stamped "18K 0.750". I would appreciate it if someone could advise me as to whether it's a genuine Omega dial, and whether it really is solid gold. Thanks in advance!

 

A bit of an odd thing.
I would say that in general, the golden dials would not have patina the way yours does. It might be the layer of lacquer that is showing the patina.
The hourmarkers seem to be adjusted 'a bit off', meaning: the do not align neat and even with the minute-marker signs of the dial. The 12 is more or less even, bit the 2 is way off. I do not think that Omega would have a dial like this leave the factory.
The 'omega' lettering and font might be better assessed with a more sharp pic. From this pics, I think the Swiss Made is too big.
What is the size of the dial?

 

Hi Willem, thanks for your reply. The dial only measures 16mm, which is why it's difficult to take a good pic, especially with my cheap, outdated camera The patina comes off when you scratch it, so it's definitely only surface deep. I think the appearance of the 2 o'clock marker may just be due to the camera angle, as it looks alright in real life. Like you I'm a bit concerned about the lettering and style of the dial, as I haven't seen this design of Omega dial before.

Update: Whilst looking through the other dials I found another one that's also hallmarked "18K 0.750". Once again I apologize for the poor quality photography, as the hallmark may not be visible.

 

So it is a Lady's watch most likely. Not too familiar with those ones as in 'I have no expertise'.
At the same time, I think the hourmarkers are too rough and not well aligned. Front only for further investigation.

On your 2nd dial: the 'Swiss made' is really below par: the letters are completely out of line (in many ways...;-)
I have not seen many backsides to have an opinion, only that I think Omega would not place the 18K/.750 there, where the rivets of the hourmarkers would be fastened to the dial.
Looking at the two of them: strikes me that the discoloration of the two dials are exactly the same; for me a tell-tale sign that they both are not the genuine thing, esp. combined with lettering, font and 'roughness' of the dials.
Not that I want to be unpleasant, but I would walk away from them in a hurry!