Mrchntmarine
...This is somethinig i sometimes struggle with - to build 1st then prime and paint. Prime 1st then build then paint or what...
I tend to follow a sequence that makes sense to me. That's usually to clean the parts, prime most of them, especially those parts that cannot be primed once they are attached, paint those parts or assemblies that cannot be painted once they're in place, and then paint the exterior. That's just a guideline, though, not a hard and fast rule.
Whether the items in the photos in the magazine were permanently attached before the modeler painted the exterior, whether they were tacked in place, or something else, I'm afraid I can't say.
I'll just sum up by repeating-follow the sequence that makes sense to you.