That Avatar is made by Free - using the New Royal design, so a very different machine.
Singer was making the 28/128 long before Standard made the hexagon. However after Singer bought Osann, the rebranded what was left of the "hexagon" parts and sold them as the 128-8.
And it's very possible they incorporated some design features into future 128's, would have to find a picture of an older one to see how different they are.
Sort of like what Singer did when they bought out Wheeler Wilson and sold the W9 for a short period of time until all the parts were gone.