Both 2005 Specialized Roubaixs but one is an "Elite" and the other a "Comp". Website lists both the discription and geometry the same. Basically, both are blue but just with a different model name on the top tube. Just need to confirm same layup method/technology. I'm thinking the only difference between the 2005 Elite and Comp was level of componentry.

At what level frame/fork DOES the layup change?

The Pro and Comp of that year were the same. The Pro had a matte black finish, comp had a glossy black finish.

The elite was a glossy blue finish, and used a different grade/layup of carbon. They all came from the same mold.

Down from the elite was the standard roubaix, which was aluminum with carbon stays - I think it came in blue and white. In later years the comp got downgraded to be a lower end model, but in 2005 it was nearly the same as a pro, but with downspec'd wheels and a few other bits. It even had several dura-ace parts, due to the shortage of ultegra 10 speed parts that season. I sold a handful of those bikes that season, and purchased a Comp for myself, debating if it was worth it to get the pro instead. For my needs/plans it wasn't. I still have a bit of memory given over to that line of bikes.

Under technical specs, both the Comp and Elite frame/ fork descriptions look the same to me, but check it out for yourself.
http://www.specialized.com/bc/SBCBkModel.jsp?arc=2005&sid=05Roubaix

Specialized also removes a bunch of details from the product pages when they go to archival. As a salesman, the info I had supported that they were different layups.

Who knows. That was three years ago.