It would be a little abnormal—depending on how tight he likes his clothes he might need a little custom tailoring, and fully covered, one arm would still appear to be a little bulkier in a way that could be mistaken for being extra swole (or just swollen) compared to the other. But it wouldn't be a hulk arm.

As a footnote, his arm being golemized wouldn't come with any superhuman strength or anything, just the durability and lack of sensation. That may be what you were already assuming, but again spelling it out just in case!