Hi, caseback seems ok, probably gold plate. I think it could be a good timeteller but if you don't mind me asking; what appeals to you about this watch? As a sidenote: the case is usually badly affected by those straps so you might want to ask for better pictures or walk away if you're bothered by damage to the lugs. Vulcain make cool watches but this doesn't house an in-house caliber btw.
Here's a picture of a Vulcain movement designed 50 years prior to the posted watch.
View attachment 1400624
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