No expert on these but I think bracelet is legit. Buckle lengths, expansion links and references were all transitioning around this time.
See below pics
4/60 7077 transitional with short buckle, fixed expansion links
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2/61 transitional no reference 7912 with large buckle, fixed expansion links
View attachment 834895
3/61 transitional no reference 7912 with large buckle, fixed expansion links
View attachment 834892
3/61 Reference 7912 with removable expansion links
View attachment 834893
Click to expand...