Appreciate any help Identifying this gold Omega. My fathers watch for ca 50 years. Bought in the UK at what I guess would be the mid to late 60s. The crown and crystal were replaced in the early to mid eighties with non Omega parts. Lugs distance is 18mm so I’d estimate the case size to be ca 35mm. Any help identifying the model ref or rough model name would be much appreciated. manual wind, never been serviced (! ) but still runs great with good time keeping.