Sorry I said romeo when I meant romeo 2.I read this to quickly. Romeo 2 did contain a sku number printed on the arm, they were not completely blank. As far as serial numbers are concerned Romeo 1 had serial numbers so I believe your post requires some clarification. View attachment 595963
If they were launched in 2004 that was after they stopped marking them with serial numbers and prior to marking them with Sku numbers. I am speculating but I would expect there to be romeo 2 out there with no serial and sku and later romeos with a sku. The only reason would not be is they discontinued the romeo 2 prior to adding sku numbers to the x-metals