I purchased this watch in February 1969 while stationed on the USS Forestall CVA-59, I paid $250 a months pay for a E3 Airman.I had the watch rebuilt recently by Jeff Herman of watchrepair.net and added a Presentation sapphire case back.
Jeff does excellent work &, uses all Omega parts.
Thank You Jeff I will get another 50 years out of this watch! ( or my son will)

 

I wasn’t aware that a display back was available for the vintage MkII. Could you provide any info on where you obtained it? I have a candidate for one....

 

It'as guy in Germany who make them. rather nicely made for about 80 euros. His name is Thomas Preik.
http://www.customwatchconcepts.com/product_info.php?products_id=21